diff --git a/.github/actions/install-qt-support/action.yml b/.github/actions/install-qt-support/action.yml
index 15e7a22a6..66b98ab7e 100644
--- a/.github/actions/install-qt-support/action.yml
+++ b/.github/actions/install-qt-support/action.yml
@@ -20,6 +20,7 @@ runs:
       sudo apt-get install libxcb-render-util0
       sudo apt-get install libxcb-xinerama0
       sudo apt-get install libxcb-shape0
+      sudo apt-get install libxcb-cursor0
       sudo apt-get install pulseaudio
       sudo apt-get install libpulse-mainloop-glib0
       # Needed to work around https://bugreports.qt.io/browse/PYSIDE-1547
diff --git a/.github/workflows/test-docs-with-edm.yml b/.github/workflows/test-docs-with-edm.yml
new file mode 100644
index 000000000..f9733e920
--- /dev/null
+++ b/.github/workflows/test-docs-with-edm.yml
@@ -0,0 +1,56 @@
+# This workflow targets stable released dependencies from EDM.
+# Note that some packages may not actually be installed from EDM but from
+# PyPI, see etstool.py implementations.
+
+name: Build docs with EDM
+
+on: [pull_request, workflow_dispatch]
+
+env:
+  INSTALL_EDM_VERSION: 3.5.0
+  QT_MAC_WANTS_LAYER: 1
+
+jobs:
+
+  # Build docs using EDM packages
+  docs-with-edm:
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        toolkit: ['pyside6']
+      fail-fast: false
+    timeout-minutes: 20  # should be plenty, it's usually < 5
+    runs-on: ${{ matrix.os }}
+    env:
+      # Set root directory, mainly for Windows, so that the EDM Python
+      # environment lives in the same drive as the cloned source. Otherwise
+      # 'pip install' raises an error while trying to compute
+      # relative path between the site-packages and the source directory.
+      EDM_ROOT_DIRECTORY: ${{ github.workspace }}/.edm
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install Qt dependencies
+        uses: ./.github/actions/install-qt-support
+        if: matrix.toolkit != 'wx'
+      - name: Cache EDM packages
+        uses: actions/cache@v3
+        with:
+          path: ~/.cache
+          key: ${{ runner.os }}-${{ matrix.toolkit }}-${{ hashFiles('etstool.py') }}
+      - name: Setup EDM
+        uses: enthought/setup-edm-action@v2
+        with:
+          edm-version: ${{ env.INSTALL_EDM_VERSION }}
+      - name: Install click to the default EDM environment
+        run: edm install -y wheel click coverage
+      - name: Install test environment
+        run: edm run -- python etstool.py install --toolkit=${{ matrix.toolkit }}
+      - name: Build docs
+        run: xvfb-run -a edm run -- python etstool.py docs --toolkit=${{ matrix.toolkit }}
+      - name: Archive HTML docs
+        uses: actions/upload-artifact@v3
+        with:
+          name: html-doc-bundle
+          path: docs/build/html
+          # don't need these kept for long
+          retention-days: 7
diff --git a/.github/workflows/test-with-edm.yml b/.github/workflows/test-with-edm.yml
index 8f72f1a08..917c71e3d 100644
--- a/.github/workflows/test-with-edm.yml
+++ b/.github/workflows/test-with-edm.yml
@@ -16,6 +16,8 @@ jobs:
   test-with-edm:
     strategy:
       matrix:
+        # Note: MacOS support is contingent on not hitting any issues with
+        # unsupported CPU features such as AVX2 and so may be unstable.
         os: [ubuntu-latest, macos-latest, windows-latest]
         toolkit: ['pyside6']
       fail-fast: false
diff --git a/.gitignore b/.gitignore
index 853bfd569..0a46cb31c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@
 build/
 dist/
 docs/build/
+docs/source/api
 
 # Auto-generated by setup.py
 pyface/_version.py
diff --git a/CHANGES.txt b/CHANGES.txt
index b49dbfa1d..3e6c80236 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -2,6 +2,154 @@
 Pyface Changelog
 ================
 
+Release 8.0.0
+=============
+
+Highlights of this release
+--------------------------
+
+This is a major release which removes a number of things which have been
+deprecated for a number of years.  The most significant change in this release
+is that the Qt toolkit backend has been moved from the ``pyface.ui.qt4``
+package to the ``pyface.ui.qt`` package.  The "qt4" namespace had been an
+ongoing source of confusion as Qt5 and Qt6 became the most popular versions of
+Qt in use. Because this change has the potential to cause significant backwards
+compatibility issues, this release includes import hooks to continue to support
+imports from ``pyface.ui.qt4...`` which can be enabled by:
+
+- using "qt4" for the `ETS_TOOLKIT` or `ETSConfig.toolkit` values.
+- setting the `ETS_QT4_IMPORT` environment variable to a non-empty value
+- explicitly adding the import hooks to `sys.meta_path`
+
+In particular the environment variables allow users of ETS-based applications
+such as Mayavi to continue to use those applications with newer versions of
+Pyface until there is time to update their code to the new import locations.
+
+Additionally this release uses the module-level ``__getattr__`` system
+introduced in Python 3.7 to delay imports from the ``api`` modules which have
+side-effects, particularly toolkit selection.  This means that you can, for
+example, import ``pyface.api`` and toolkit selection will be deferred until
+you actually request a class or object which is toolkit-dependent.  Part of
+this included adding formal interfaces for ``ActionManager`` and its subclasses
+
+In addition this release:
+
+- adds support for Python 3.11 and drops support for Python 3.6
+- adds support for PySide 6.4+ and the new enum system
+- removes code supporting PyQt4, and supports more modern imports from
+  `pyface.qt`, such as `pyface.qt.QtWidgets`.
+- removes many things flagged as deprecated in Pyface 7
+- consistently add interface classes to ``api`` modules.
+- adds new Field subclasses, including an ImageField and LabelField
+- moves to a pyproject.toml-based packaging solution, removing setup.py
+
+Detailed changes
+----------------
+
+Thanks to:
+
+* Mark Dickinson
+* Dominik Gresch
+* JaRoSchm
+* Rahul Poruri
+* Corran Webster
+
+Features
+
+* Refactor IField and add IImageField and ILabelField Field classes (#1234)
+* Move ``pyface.ui.qt4`` to ``pyface.ui.qt`` (#1223, #1228)
+* Delayed imports with side-effects in ``api`` modules; new interfaces for
+  ``ActionManager`` and its subclasses (#1229)
+
+Enhancements
+
+* Better handling of sizes for multiple (or no) screens (#1237)
+* More arguments for the ``confirm`` function (#1221)
+* Expose interfaces in ``api`` modules and other improvemnts to ``api`` modules
+  (#1220, #1222, #1229)
+* remove deprecated modules and code (#1209, #1215)
+* PySide 6.5 support (#1238)
+* Python 3.11 and PySide 6.4 support (#1210)
+
+Fixes
+
+* Always use a no-delay timer for ``GUI`` ``invoke_later`` and
+  ``set_trait_later`` on Qt (#1226)
+* Work arounds for some end-of-process segfaults on PySide < 6.4.3 (#1214)
+* Use ``exec`` instead of ``exec_`` where possible (#1208)
+* Emit a warning rather than asserting in SplitTabWidget (#1192)
+* Remove required parent argument in Wx StatusBarManager (#1192)
+* Use integer division in DockSplitter.draw (#1190)
+
+Documentation
+
+* general updates and enhancements (#1238)
+* update copyright dates (#1191)
+
+CI
+
+* remove ``setup.py`` and use ``pyproject.toml`` (#1203, #1214)
+
+Release 7.4.4
+=============
+
+Highlights of this release
+--------------------------
+
+This is a quick bugfix release that resolves some issues with the 7.4.3 release
+on CI for downstream projects.  The issues were on testing code, and so
+shouldn't impact application code or behaviour.
+
+Detailed changes
+----------------
+
+Thanks to:
+
+* Corran Webster
+
+Fixes
+
+* Don't raise ConditionTimeoutError if test doesn't time out (#1182)
+
+CI
+
+* get CI working again with ubuntu-current on GitHub (#1186)
+
+Release 7.4.3
+=============
+
+Highlights of this release
+--------------------------
+
+This is a bugfix release that collects a number of additional issues discovered
+and fixed since the 7.4.2 release.  Among the fixes, this pins PySide6 to less than
+6.4.0, as 6.4 has breaking changes in it.
+
+Detailed changes
+----------------
+
+Thanks to:
+
+* Alex Chabot-Leclerc
+* Mark Dickinson
+* Eric Larson
+* Steven Kern
+* Corran Webster
+
+Fixes
+
+* Fix code editor gutter widget on recent Python versions (#1176)
+* fix issues with FileDialog and DirectoryDialog close method on Linux (#1175)
+* update setup.py metadata (#1173)
+* restrict to PySide versions before 6.4.0 (#1169)
+* don't do unneccessary evaluations of conditions in EventLoopHelper (#1168)
+* fix a deleted object error in PyQt5 (#1161)
+* better reporting of toolkit errors (#1157)
+
+Documentation
+
+* fix some Python 2 style print statements in documentation (#1157)
+
 Release 7.4.2
 =============
 
diff --git a/README.rst b/README.rst
index 718e977bf..58a70a812 100644
--- a/README.rst
+++ b/README.rst
@@ -3,10 +3,12 @@ Pyface: Traits-capable Windowing Framework
 ==========================================
 
 The Pyface project contains a toolkit-independent GUI abstraction layer,
-which is used to support the "visualization" features of the Traits package.
-Thus, you can write code in terms of the Traits API (views, items, editors,
-etc.), and let Pyface and your selected toolkit and back-end take care of
-the details of displaying them.
+which is used to support the "visualization" features of the Enthought Tool
+Suite libraries.  Pyface contains Traits-aware wrappers of standard GUI
+elements such as Windows, Dialogs and Fields, together with the "Tasks"
+application framework which provides a rich GUI experience with dock panes,
+tabbed editors, and so forth.  This permits you to write cross-platform
+interactive GUI code without needing to use the underlying GUI backend.
 
 The following GUI backends are supported:
 
@@ -14,33 +16,79 @@ The following GUI backends are supported:
 - PyQt5 (stable) and PyQt6 (in development)
 - wxPython 4 (experimental)
 
+Example
+-------
+
+The following code creates a window with a simple Python shell:
+
+..  code-block:: python
+
+    from pyface.api import ApplicationWindow, GUI, IPythonShell
+
+    class MainWindow(ApplicationWindow):
+        """ The main application window. """
+
+        #: The PythonShell that forms the contents of the window
+        shell = Instance(IPythonShell, allow_none=False)
+
+        def _create_contents(self, parent):
+            """ Create the editor. """
+            self.shell.create(parent)
+            return self.shell.control
+
+        def destroy(self):
+            self.shell.destroy()
+            super().destroy()
+
+        def _shell_default(self):
+            from pyface.api import PythonShell
+            return PythonShell()
+
+    # Application entry point.
+    if __name__ == "__main__":
+        # Create the GUI.
+        gui = GUI()
+
+        # Create and open the main window.
+        window = MainWindow(title="Python Shell", size=(640, 480))
+        window.open()
+
+        # Start the GUI event loop!
+        gui.start_event_loop()
+
+..  image:: https://raw.github.com/enthought/pyface/main/shell_window.png
+    :alt: A Pyface GUI window containing a Python shell.
+
 Installation
 ------------
 
-GUI backends are marked as optional dependencies of Pyface. Some features
-or infrastructures may also require additional dependencies.
+Pyface is a pure Python package.  In most cases Pyface will be installable
+using a simple ``pip install`` command.
 
-To install with PySide2 dependencies::
+To install with a backend, choose one of the following, as appropriate:
 
-    $ pip install pyface[pyside2]
+..  code-block:: console
 
-To install with PySide6 dependencies (experimental)::
+    $ pip install pyface[pyside2]
 
     $ pip install pyface[pyside6]
 
-To install with PyQt5 dependencies::
-
     $ pip install pyface[pyqt5]
 
-To install with wxPython4 dependencies (experimental)::
-
     $ pip install pyface[wx]
 
-``pillow`` is an optional dependency for the PILImage class::
+Some optional functionality uses ``pillow`` and ``numpy`` and these can be
+installed using optional dependencies:
+
+..  code-block:: console
 
     $ pip install pyface[pillow]
 
-To install with additional test dependencies::
+    $ pip install pyface[numpy]
+
+For running tests a few more packages are required:
+
+..  code-block:: console
 
     $ pip install pyface[test]
 
@@ -51,20 +99,6 @@ Documentation
 
 * `API Documentation <http://docs.enthought.com/pyface/api/pyface.html>`_.
 
-Prerequisites
--------------
-
-Pyface depends on:
-
-* `Traits <https://github.com/enthought/traits>`_
-
-* a GUI toolkit as described above
-
-* Pygments for syntax highlighting in the Qt code editor widget.
-
-* some widgets may have additional optional dependencies such as NumPy or
-  Pillow.
-
 .. end_of_long_description
 
 Developing Pyface
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 8b58d78e6..3cddc233b 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -11,9 +11,10 @@
 # All configuration values have a default value; values that are commented out
 # serve to show the default value.
 
-import os
-import runpy
-import sys
+try:
+    from importlib.metadata import version as metadata_version
+except:
+    from importlib_metadata import version as metadata_version
 
 # General configuration
 # ---------------------
@@ -45,10 +46,7 @@
 
 # The default replacements for |version| and |release|, also used in various
 # other places throughout the built documents.
-version_py = os.path.join('..', '..', 'pyface', '_version.py')
-version_content = runpy.run_path(version_py)
-version = ".".join(version_content["version"].split(".", 2)[:2])
-release = version
+version = release = metadata_version("pyface")
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
diff --git a/docs/source/fields.rst b/docs/source/fields.rst
index ac6d12639..2bb7c4049 100644
--- a/docs/source/fields.rst
+++ b/docs/source/fields.rst
@@ -9,16 +9,81 @@ to a Traits interface, so that you can use them in a cross-toolkit manner.
 
 Where possible, these classes share a common API for the same functionality.
 In particular, all classes have a
-:py:attr:`~pyface.fields.i_field.IField.value` trait which holds the (usually
-user-editable) value displayed in the field.  Code using the field can listen
-to changes in this trait to react to the user entering a new value for the
-field without needing to know anything about the underlying toolkit event
-signalling mechanisms.
+:py:attr:`~pyface.fields.i_field.IField.value` trait which holds the value
+displayed in the field.
 
-All fields also provide a trait for setting the
-:py:attr:`~pyface.fields.i_field.IField.context_menu` of the field. Context
-menus should be :py:class:`~pyface.action.menu_manager.MenuManager`
-instances.
+Fields where the value is user-editable rather than simply displayed implement
+the :py:attr:`~pyface.fields.i_editable_field.IEditableField` interface.  Code
+using the field can listen to changes in the value trait to react to the user
+entering a new value for the field without needing to know anything about the
+underlying toolkit event signalling mechanisms.
+
+Fields inherit from :py:class:`~pyface.i_widget.IWidget` and
+:py:class:`~pyface.i_layout_item.ILayoutItem` which have a number of
+additional traits with useful features:
+
+:py:attr:`~pyface.i_widget.IWidget.tooltip`
+    A tooltip for the widget, which should hold string.
+
+:py:attr:`~pyface.i_widget.IWidget.context_menu`
+    A context menu for the widget, which should hold an
+    :py:class:`~pyface.action.i_menu_manager.IMenuManager` instance.
+
+:py:attr:`~pyface.i_layout_item.ILayoutItem.minimum_size`
+    A tuple holding the minimum size of a layout widget.
+
+:py:attr:`~pyface.i_layout_item.ILayoutItem.maximum_size`
+    A tuple holding the minimum size of a layout widget.
+
+:py:attr:`~pyface.i_layout_item.ILayoutItem.stretch`
+    A tuple holding information about the distribution of addtional space into
+    the widget when growing in a layout.  Higher numbers mean proportinally
+    more space.
+
+:py:attr:`~pyface.i_layout_item.ILayoutItem.size_policy`
+    A tuple holding information about how the widget can grow and shrink.
+
+:py:attr:`~pyface.fields.i_field.IField.alignment`
+    A value holding the horizontal alignment of the contents of the field.
+
+ComboField
+==========
+
+The :py:class:`~pyface.fields.i_combo_field.IComboField` interface has an arbitrary
+:py:attr:`~pyface.fields.i_combo_field.IComboField.value` that must come from a list
+of valid :py:attr:`~pyface.fields.i_combo_field.IComboField.values`.  For non-text
+values, a :py:attr:`~pyface.fields.i_combo_field.IComboField.formatter` function
+should be provided, defaulting to :py:func:`str`.
+
+LabelField
+==========
+
+The :py:class:`~pyface.fields.i_label_field.ILabelField` interface has a string
+for the :py:attr:`~pyface.fields.i_label_field.ILabelField.value` which is not
+user-editable.
+
+In the Qt backend they can have an image for an
+:py:attr:`~pyface.fields.i_label_field.ILabelField.icon`.
+
+ImageField
+==========
+
+The :py:class:`~pyface.fields.i_image_field.IImageField` interface has an
+:py:class:`~pyface.i_image.IImage` for its
+:py:attr:`~pyface.fields.i_image_field.IImageField.value` which is not
+user-editable.
+
+SpinField
+=========
+
+The :py:class:`~pyface.fields.i_spin_field.ISpinField` interface has an integer
+for the :py:attr:`~pyface.fields.i_spin_field.ISpinField.value`, and also
+requires a range to be set, either via setting the min/max values as a tuple to
+the :py:attr:`~pyface.fields.i_spin_field.ISpinField.bounds` trait, or by setting
+values individually to :py:attr:`~pyface.fields.i_spin_field.ISpinField.minimum`
+and :py:attr:`~pyface.fields.i_spin_field.ISpinField.maximum`.  The
+:py:attr:`~pyface.fields.i_spin_field.ISpinField.wrap` trait determines whether
+the spinner wraps around at the extreme values.
 
 TextField
 =========
@@ -41,26 +106,6 @@ the Qt backend has a number of other options as well).  The text field can be
 set to read-only mode via the
 :py:attr:`~pyface.fields.i_text_field.ITextField.read_only` trait.
 
-SpinField
-=========
-
-The :py:class:`~pyface.fields.i_spin_field.ISpinField` interface has an integer
-for the :py:attr:`~pyface.fields.i_spin_field.ISpinField.value`, and also
-requires a range to be set, either via setting the min/max values as a tuple to
-the :py:attr:`~pyface.fields.i_spin_field.ISpinField.range` trait, or by setting
-values individually to :py:attr:`~pyface.fields.i_spin_field.ISpinField.minimum`
-and :py:attr:`~pyface.fields.i_spin_field.ISpinField.maximum`.
-
-ComboField
-==========
-
-The :py:class:`~pyface.fields.i_combo_field.IComboField` interface has an arbitrary
-:py:attr:`~pyface.fields.i_combo_field.IComboField.value` that must come from a list
-of valid :py:attr:`~pyface.fields.i_combo_field.IComboField.values`.  For non-text
-values, a :py:attr:`~pyface.fields.i_combo_field.IComboField.formatter` function
-should be provided - this defaults to either :py:func:`str` (Python 3+) or
-:py:func:`unicode` (Python 2).
-
 TimeField
 ==========
 
diff --git a/docs/source/index.rst b/docs/source/index.rst
index 21281763e..d2c16fd55 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -7,26 +7,25 @@ the TraitsUI package. Thus, you can write code in the abstraction of the
 Pyface API and the selected toolkit and backend take care of the details of
 displaying them.
 
-Pyface
-======
-
 Pyface enables programmers to interact with generic GUI objects, such as an
-"MDI Application Window", rather than with raw GUI widgets. (Pyface is named by
-analogy to JFace in Java.) TraitsUI uses Pyface to implement views and editors
-for displaying and editing Traits-based objects.
+"Application Window", rather than with raw GUI widgets.  TraitsUI uses Pyface
+to implement views and editors for displaying and editing Traits-based objects.
+In addition to wrappers around fields and dialogs, Pyface includes an
+application framework called "Tasks" for building full-featured
+applications featuring dock panes, tabbed editor areas and so forth.
 
 Toolkit Backends
 ================
 
-TraitsUI and Pyface define APIs that are independent of any GUI toolkit.
-However, in order to actually produce user interfaces with them, you must
+Pyface defines APIs that are independent of any GUI toolkit.  However, in
+order to actually produce user interfaces with them, you must
 install a supported Python-based GUI toolkit and the appropriate
 toolkit-specific backend project. Conversely, a "null" backend is
 automatically used in the absence of a real backend.
 
 Currently, the GUI toolkits are
 
-* PySide2 (stable) and PySide6 (experimental)
+* PySide2 and PySide6 (stable)
 * PyQt5 (stable) and PyQt6 (in development)
 * wxPython 4 (experimental)
 
diff --git a/docs/source/toolkits.rst b/docs/source/toolkits.rst
index 5bc91eaa2..9960000c8 100644
--- a/docs/source/toolkits.rst
+++ b/docs/source/toolkits.rst
@@ -23,9 +23,10 @@ ways:
     from tratis.etsconfig.api import ETSConfig
     ETSConfig.toolkit = 'qt'
 
-  This must be done _before_ any widget imports in your application, including
-  importing :py:mod:`pyface.api`.  Precisely, this must be set before the
-  first import of :py:mod:`pyface.toolkit`.
+  This must be done _before_ any widget imports in your application.
+  Precisely, this must be set before the first call to
+  :py:func:`pyface.base_toolkit.find_toolkit` (which usually happens
+  as a side-effect of importing :py:mod:`pyface.toolkit`).
 
 If for some reason Pyface can't load a deliberately specified toolkit, then it
 will raise an exception.
@@ -35,6 +36,14 @@ toolkits, in that order, and then any other toolkits that it knows about
 other than ``null``.  If all of those fail, then it will try to load the
 ``null`` toolkit.
 
+Pyface tries to defer toolkit selection as long as possible until it is
+actually needed because importing a toolkit tends to be slow and have
+significant side-effects. Very occasionally an application or test suite may
+need to ensure that the toolkit has been selected (for example, to enable
+"ui" dispatch from background threads in Traits).  This can be achieved by
+either importing :py:mod:`pyface.toolkit` or, more directly, by calling
+:py:func:`pyface.base_toolkit.find_toolkit`.
+
 Once selected, the toolkit infrastructure is largely transparent to the
 application.
 
diff --git a/docs/source/traits.rst b/docs/source/traits.rst
index 2be140880..b3391c580 100644
--- a/docs/source/traits.rst
+++ b/docs/source/traits.rst
@@ -32,13 +32,20 @@ color spaces, such as HSV or HLS::
 which allow specification of colors via CSS-style color strings, such as::
 
     Color.from_str("aquamarine")
-    Color.from_str("#662244")
+    Color.from_str("#662244cc")
 
-All standard web colors are understood, as well as hexadecimal RGB(A) with
-1, 2 or 4 hex digits per channel.
+All `standard web colors <https://en.wikipedia.org/wiki/Web_colors#Extended_colors>`_
+are understood, as well as hexadecimal RGB(A) with 1, 2 or 4 hex digits per
+channel.
 
 |Color| instances are mutable, as their intended use is as values stored
-in |PyfaceColor| trait classes which can be modified and listened to.  The
+in |PyfaceColor| trait classes which can be modified and listened to.  This
+means that they are comparatively heavyweight objects and should be shared
+where possible and aren't particularly suited for situations where large
+numbers of distinct and independent colors are needed: NumPy arrays are likely
+better suited for this sort of application.
+
+The
 |PyfaceColor| validator understands string descriptions of colors, and will
 accept them as values when initializing or modifying the trait::
 
@@ -64,8 +71,96 @@ building applications on top of Pyface.
 It is intended that this trait will eventually replace the ``Color``
 trait from TraitsUI.
 
+Fonts
+=====
+
+Just as with colors, it is common to want to be able to specify the font to use
+for text in the UI.  Each toolkit usually has its own way of representing
+fonts, and so the ability to specify a font in a toolkit-independent way that
+can be converted to a toolkit-specific representation is important.  This is
+particularly so when you want to allow the user to specify a font.
+
+Pyface provides a |Font| class and a corresponding |PyfaceFont| trait-type
+that allows this sort of representation.  Internally, the |Font| class
+stores font attributes such as |Font.weight| or |Font.size| as traits::
+
+    font = Font(family=["Comic Sans"], size=24, weight="bold")
+    font.weight
+
+Some of these attributes are mapped traits, or otherwise convert string
+values to numeric values.  For example |Font.size| will accept strings like
+"12pt", while |Font.weight| holds a numeric weight value in a mapped
+attribute::
+
+..  code-block:: pycon
+
+    >>> font.weight
+    "bold"
+    >>> font.weight_
+    700
+
+|Font| instances are mutable, as their intended use is as values stored
+in |PyfaceFont| trait classes which can be modified and listened to.
+
+As a convenience, the |PyfaceFont| validator understands string descriptions
+of fonts, and will accept them as values when initializing or modifying the
+trait::
+
+    class Style(HasStrictTraits):
+
+        font = PyfaceFont("24 pt Bold Comic Sans")
+
+        @observe('font.*')
+        def font_changed(self, event):
+            print('The font has changed to {}'.format(self.font))
+
+    style = Style(font='12 italc Helvetica')
+    style.font.weight = 'light'
+    style.font = Font(
+        family=["Helvetica", "Arial", "sans-serif"],
+        variants={"small-caps"},
+    )
+
+The parsing of strings to fonts is currently handled by a |simple_parser| that
+is modelled on the ``Font`` trait from TraitsUI, but it can be substituted
+for a more sophisticated one, if needed.
+
+For interactions with the toolkit, the |Font.from_toolkit| and
+|Font.to_toolkit| methods allow conversion to and from the appropriate
+toolkit font objects, such as Qt's :py:class:`QFont` or
+:py:class:`wx.Font`.  These are most likely to be needed by internal
+Pyface functionality, and should not be needed by developers who are
+building applications on top of Pyface.
+
+It is intended that this trait will eventually replace the ``Font``
+trait from TraitsUI.  It is also likely that the simple parser will be replaced
+with a parser that understands CSS-like font strings.
+
+Layout Traits
+=============
+
+Pyface also provides a number of classes and traits to assist with
+layout-related functionality.  These include the convenience Enums |Alignment|,
+|Orientation| and |Position| as well as the classes |Margin| and |Border| and
+their corresponding traits |HasMargin| and |HasBorder|.
+
+
+.. |Alignment| replace:: :py:attr:`~pyface.ui_traits.Alignment`
+.. |Border| replace:: :py:class:`~pyface.ui_traits.Border`
 .. |Color| replace:: :py:class:`~pyface.color.Color`
 .. |Color.from_str| replace:: :py:meth:`~pyface.color.Color.from_str`
 .. |Color.from_toolkit| replace:: :py:meth:`~pyface.color.Color.from_toolkit`
 .. |Color.to_toolkit| replace:: :py:meth:`~pyface.color.Color.to_toolkit`
+.. |Font| replace:: :py:class:`~pyface.font.Font`
+.. |Font.size| replace:: :py:attr:`~pyface.font.Font.size`
+.. |Font.from_toolkit| replace:: :py:meth:`~pyface.font.Font.from_toolkit`
+.. |Font.to_toolkit| replace:: :py:meth:`~pyface.font.Font.to_toolkit`
+.. |Font.weight| replace:: :py:attr:`~pyface.font.Font.weight`
+.. |HasMargin| replace:: :py:class:`~pyface.ui_traits.HasMargin`
+.. |HasBorder| replace:: :py:class:`~pyface.ui_traits.HasBorder`
+.. |Margin| replace:: :py:class:`~pyface.ui_traits.Margin`
+.. |Orientation| replace:: :py:attr:`~pyface.ui_traits.Orientation`
+.. |Position| replace:: :py:attr:`~pyface.ui_traits.Position`
 .. |PyfaceColor| replace:: :py:class:`~pyface.ui_traits.PyfaceColor`
+.. |PyfaceFont| replace:: :py:class:`~pyface.ui_traits.PyfaceFont`
+.. |simple_parser| replace:: :py:func:`~pyface.util.font_parser.simple_parser`
diff --git a/etstool.py b/etstool.py
index 6d661394f..4272abdf6 100644
--- a/etstool.py
+++ b/etstool.py
@@ -95,7 +95,6 @@
     "importlib_resources>=1.1.0",
     "traits" + TRAITS_VERSION_REQUIRES,
     "traitsui",
-    "numpy",
     "pygments",
     "coverage",
     "flake8",
@@ -112,8 +111,10 @@
     )
     if b'AVX2' in result.stdout.split():
         dependencies.add('pillow_simd')
+        dependencies.add('numpy')
 else:
     dependencies.add('pillow_simd')
+    dependencies.add('numpy')
 
 
 source_dependencies = {
diff --git a/examples/application/hello_world/hello_application.py b/examples/application/hello_world/hello_application.py
index ebe5d36a1..e1cab73c6 100644
--- a/examples/application/hello_world/hello_application.py
+++ b/examples/application/hello_world/hello_application.py
@@ -17,9 +17,9 @@
 computation.
 """
 
-
 import argparse
-from pyface.application import Application
+
+from pyface.api import Application
 from traits.api import Str
 
 
diff --git a/pyface/action/action.py b/pyface/action/action.py
index 2542ac982..526c07f32 100644
--- a/pyface/action/action.py
+++ b/pyface/action/action.py
@@ -124,7 +124,7 @@ def perform(self, event):
 
         Parameters
         ----------
-        event : ActionEvent instance
+        event : ActionEvent
             The event which triggered the action.
         """
         if self.on_perform is not None:
diff --git a/pyface/action/action_controller.py b/pyface/action/action_controller.py
index d8ddf9379..b2c926df9 100644
--- a/pyface/action/action_controller.py
+++ b/pyface/action/action_controller.py
@@ -25,14 +25,14 @@ def perform(self, action, event):
 
         Parameters
         ----------
-        action : Action instance
+        action : Action
             The action to perform.
-        event : ActionEvent instance
+        event : ActionEvent
             The event that triggered the action.
 
         Returns
         -------
-        result : any
+        result : Any
             The result of the action's perform method (usually None).
         """
         return action.perform(event)
@@ -42,7 +42,7 @@ def can_add_to_menu(self, action):
 
         Parameters
         ----------
-        action : Action instance
+        action : Action
             The action to consider.
 
         Returns
@@ -57,7 +57,7 @@ def add_to_menu(self, action):
 
         Parameters
         ----------
-        action : Action instance
+        action : Action
             The action added to the menu.
         """
         pass
@@ -67,7 +67,7 @@ def can_add_to_toolbar(self, action):
 
         Parameters
         ----------
-        action : Action instance
+        action : Action
             The action to consider.
 
         Returns
@@ -82,7 +82,7 @@ def add_to_toolbar(self, action):
 
         Parameters
         ----------
-        action : Action instance
+        action : Action
             The action added to the toolbar.
         """
         pass
diff --git a/pyface/action/action_item.py b/pyface/action/action_item.py
index 987ab1b02..d9744383c 100644
--- a/pyface/action/action_item.py
+++ b/pyface/action/action_item.py
@@ -93,7 +93,7 @@ def add_to_menu(self, parent, menu, controller):
             The parent of the new menu item control.
         menu : toolkit menu
             The menu to add the action item to.
-        controller : ActionController instance or None
+        controller : pyface.action.action_controller.ActionController  or None
             The controller to use.
         """
         if (controller is None) or controller.can_add_to_menu(self.action):
@@ -117,9 +117,9 @@ def add_to_toolbar(
             The parent of the new menu item control.
         tool_bar : toolkit toolbar
             The toolbar to add the action item to.
-        image_cache : ImageCache instance
+        image_cache : ImageCache
             The image cache for resized images.
-        controller : ActionController instance or None
+        controller : pyface.action.action_controller.ActionController  or None
             The controller to use.
         show_labels : bool
             Should the toolbar item show a label.
@@ -145,7 +145,7 @@ def add_to_palette(self, tool_palette, image_cache, show_labels=True):
             The parent of the new menu item control.
         tool_palette : toolkit tool palette
             The tool palette to add the action item to.
-        image_cache : ImageCache instance
+        image_cache : ImageCache
             The image cache for resized images.
         show_labels : bool
             Should the toolbar item show a label.
diff --git a/pyface/action/action_manager.py b/pyface/action/action_manager.py
index 29dda760c..4f2ef2703 100644
--- a/pyface/action/action_manager.py
+++ b/pyface/action/action_manager.py
@@ -45,7 +45,7 @@ class ActionManager(HasTraits):
     enabled = Bool(True)
 
     #: All of the contribution groups in the manager.
-    groups = Property(List(Group))
+    groups = Property(List(Instance(Group)), observe='_groups.items')
 
     #: The manager's unique identifier (if it has one).
     id = Str()
@@ -61,7 +61,7 @@ class ActionManager(HasTraits):
     # Private interface ----------------------------------------------------
 
     #: All of the contribution groups in the manager.
-    _groups = List(Group)
+    _groups = List(Instance(Group))
 
     # ------------------------------------------------------------------------
     # 'object' interface.
@@ -72,7 +72,7 @@ def __init__(self, *args, **traits):
 
         Parameters
         ----------
-        args : collection of strings, Group instances, or ActionManagerItem instances
+        args : collection of strings, Group instances, or ActionManagerItem s
             Positional arguments are interpreted as Items or Groups managed
             by the action manager.
 
@@ -142,7 +142,7 @@ def append(self, item):
 
         Parameters
         ----------
-        item : string, Group instance or ActionManagerItem instance
+        item : string, Group instance or ActionManagerItem
             The item to append.
 
         Notes
@@ -180,7 +180,7 @@ def insert(self, index, item):
         ----------
         index : int
             The position at which to insert the object
-        item : string, Group instance or ActionManagerItem instance
+        item : string, Group instance or ActionManagerItem
             The item to insert.
 
         Notes
@@ -213,7 +213,7 @@ def find_group(self, id):
 
         Returns
         -------
-        group : Group instance
+        group : Group
             The group which matches the id, or None if no such group exists.
         """
         for group in self._groups:
@@ -256,7 +256,7 @@ def walk(self, fn):
 
         Parameters
         ----------
-        fn : callable
+        fn : Callable
             A callable to apply to the tree of groups and items, starting with
             the manager.
         """
@@ -272,7 +272,9 @@ def walk_group(self, group, fn):
 
         Parameters
         ----------
-        fn : callable
+        group : Group
+            The group to walk.
+        fn : Callable
             A callable to apply to the tree of groups and items.
         """
         fn(group)
@@ -290,7 +292,10 @@ def walk_item(self, item, fn):
 
         Parameters
         ----------
-        fn : callable
+        item : item
+            The item to walk.  This may be a submenu or similar in addition to
+            simple Action items.
+        fn : Callable
             A callable to apply to the tree of items and subgroups.
         """
         if hasattr(item, "groups"):
@@ -309,7 +314,7 @@ def _get_default_group(self):
 
         Returns
         -------
-        group : Group instance
+        group : Group
             The manager's default group.
         """
         group = self.find_group(self.DEFAULT_GROUP)
@@ -324,7 +329,7 @@ def _prepare_item(self, item):
 
         Parameters
         ----------
-        item : string, Group instance or ActionManagerItem instance
+        item : string, Group instance or ActionManagerItem
             The item to be added to this ActionManager
 
         Returns
diff --git a/pyface/action/action_manager_item.py b/pyface/action/action_manager_item.py
index b4cf6b675..a6297ed17 100644
--- a/pyface/action/action_manager_item.py
+++ b/pyface/action/action_manager_item.py
@@ -32,7 +32,7 @@ class ActionManagerItem(HasTraits):
     id = Str()
 
     #: The group the item belongs to.
-    parent = Instance("pyface.action.api.Group")
+    parent = Instance("pyface.action.group.Group")
 
     #: Is the item enabled?
     enabled = Bool(True)
@@ -53,7 +53,7 @@ def add_to_menu(self, parent, menu, controller):
             The parent of the new menu item control.
         menu : toolkit menu
             The menu to add the action item to.
-        controller : ActionController instance or None
+        controller : pyface.action.action_controller.ActionController  or None
             The controller to use.
         """
         raise NotImplementedError()
@@ -67,9 +67,9 @@ def add_to_toolbar(self, parent, tool_bar, image_cache, controller):
             The parent of the new menu item control.
         tool_bar : toolkit toolbar
             The toolbar to add the action item to.
-        image_cache : ImageCache instance
+        image_cache : ImageCache
             The image cache for resized images.
-        controller : ActionController instance or None
+        controller : pyface.action.action_controller.ActionController  or None
             The controller to use.
         show_labels : bool
             Should the toolbar item show a label.
diff --git a/pyface/action/api.py b/pyface/action/api.py
index ad10c0ef5..82e830e87 100644
--- a/pyface/action/api.py
+++ b/pyface/action/api.py
@@ -65,10 +65,11 @@
 
 """
 
+# Imports which don't select the toolkit as a side-effect.
+
 from .action import Action
 from .action_controller import ActionController
 from .action_event import ActionEvent
-from .action_item import ActionItem
 from .action_manager import ActionManager
 from .action_manager_item import ActionManagerItem
 from .field_action import FieldAction
@@ -80,16 +81,71 @@
     ExitAction,
     GUIApplicationAction,
 )
+from .i_action_manager import IActionManager
+from .i_menu_bar_manager import IMenuBarManager
+from .i_menu_manager import IMenuManager
+from .i_status_bar_manager import IStatusBarManager
+from .i_tool_bar_manager import IToolBarManager
 from .listening_action import ListeningAction
-from .menu_manager import MenuManager
-from .menu_bar_manager import MenuBarManager
-from .status_bar_manager import StatusBarManager
-from .tool_bar_manager import ToolBarManager
 from .traitsui_widget_action import TraitsUIWidgetAction
 from .window_action import CloseWindowAction, WindowAction
 
-# This part of the module handles widgets that are still wx specific.  This
-# will all be removed when everything has been ported to PyQt and pyface
-# becomes toolkit agnostic.
 
-from traits.etsconfig.api import ETSConfig
+# ----------------------------------------------------------------------------
+# Deferred imports
+# ----------------------------------------------------------------------------
+
+# These imports have the side-effect of performing toolkit selection
+
+_toolkit_imports = {
+    'MenuManager': "menu_manager",
+    'MenuBarManager': "menu_bar_manager",
+    'StatusBarManager': "status_bar_manager",
+    'ToolBarManager': "tool_bar_manager",
+}
+
+# These are pyface.* imports that have selection as a side-effect
+# TODO: refactor to delay imports where possible
+_relative_imports = {
+    'ActionItem': "action_item",
+}
+
+
+def __getattr__(name):
+    """Lazily load attributes with side-effects
+
+    In particular, lazily load toolkit backend names.  For efficiency, lazily
+    loaded objects are injected into the module namespace
+    """
+    # sentinel object for no result
+    not_found = object()
+    result = not_found
+
+    if name in _relative_imports:
+        from importlib import import_module
+        source = _relative_imports[name]
+        module = import_module(f"pyface.action.{source}")
+        result = getattr(module, name)
+
+    elif name in _toolkit_imports:
+        from pyface.toolkit import toolkit_object
+        source = _toolkit_imports[name]
+        result = toolkit_object(f"action.{source}:{name}")
+
+    if result is not_found:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+    globals()[name] = result
+    return result
+
+
+# ----------------------------------------------------------------------------
+# Introspection support
+# ----------------------------------------------------------------------------
+
+# the list of available names we report for introspection purposes
+_extra_names = set(_toolkit_imports) | set(_relative_imports)
+
+
+def __dir__():
+    return sorted(set(globals()) | _extra_names)
diff --git a/pyface/action/field_action.py b/pyface/action/field_action.py
index 830223f72..f9848ac1e 100644
--- a/pyface/action/field_action.py
+++ b/pyface/action/field_action.py
@@ -70,7 +70,7 @@ def perform(self, event):
 
         Parameters
         ----------
-        event : ActionEvent instance
+        event : ActionEvent
             The event which triggered the action.
         """
         if self.on_perform is not None:
diff --git a/pyface/action/group.py b/pyface/action/group.py
index bd5cb1da6..3830d8f86 100644
--- a/pyface/action/group.py
+++ b/pyface/action/group.py
@@ -18,7 +18,6 @@
 
 
 from pyface.action.action import Action
-from pyface.action.action_item import ActionItem
 
 
 class Group(HasTraits):
@@ -151,6 +150,8 @@ def insert(self, index, item):
         action, and that is inserted.  If the item is a callable, then an
         Action is created for the callable, and then that is handled as above.
         """
+        from pyface.action.action_item import ActionItem
+
         if isinstance(item, Action):
             item = ActionItem(action=item)
         elif callable(item):
diff --git a/pyface/action/i_action_manager.py b/pyface/action/i_action_manager.py
new file mode 100644
index 000000000..3a4f98de7
--- /dev/null
+++ b/pyface/action/i_action_manager.py
@@ -0,0 +1,199 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+"""Interface for all action managers."""
+
+
+from traits.api import Bool, Constant, Event, Instance, Interface, List, Str
+
+from pyface.action.action_controller import ActionController
+from pyface.action.group import Group
+
+
+class IActionManager(Interface):
+    """ Abstract base class for all action managers.
+
+    An action manager contains a list of groups, with each group containing a
+    list of items.
+
+    There are currently three concrete sub-classes:
+
+    1) 'MenuBarManager'
+    2) 'MenuManager'
+    3) 'ToolBarManager'
+
+    """
+
+    # 'ActionManager' interface --------------------------------------------
+
+    #: The Id of the default group.
+    DEFAULT_GROUP = Constant("additions")
+
+    #: The action controller (if any) used to control how actions are performed.
+    controller = Instance(ActionController)
+
+    #: Is the action manager enabled?
+    enabled = Bool(True)
+
+    #: All of the contribution groups in the manager.
+    groups = List(Instance(Group))
+
+    #: The manager's unique identifier (if it has one).
+    id = Str()
+
+    #: Is the action manager visible?
+    visible = Bool(True)
+
+    # Events ----
+
+    #: fixme: We probably need more granular events than this!
+    changed = Event()
+
+    # ------------------------------------------------------------------------
+    # 'object' interface.
+    # ------------------------------------------------------------------------
+
+    def __init__(self, *items, **traits):
+        """ Creates a new action manager.
+
+        Parameters
+        ----------
+        items : collection of strings, Group, or ActionManagerItem s
+            Positional arguments are interpreted as Items or Groups
+            managed by the action manager.
+        traits : additional traits
+            Traits to be passed to the usual Traits ``__init__``.
+
+        Notes
+        -----
+
+        If a Group is passed as a positional agrument then it is added to the
+        manager and any subsequent Items arguments are appended to the Group
+        until another Group is encountered.
+
+        If a string is passed, a Group is created with id set to the string.
+        """
+
+    # ------------------------------------------------------------------------
+    # 'IActionManager' interface.
+    # ------------------------------------------------------------------------
+
+    def append(self, item):
+        """ Append an item to the manager.
+
+        Parameters
+        ----------
+        item : string, Group instance or ActionManagerItem
+            The item to append.
+
+        Notes
+        -----
+
+        If the item is a group, the Group is appended to the manager's list
+        of groups.  It the item is a string, then a group is created with
+        the string as the ``id`` and the new group is appended to the list
+        of groups.  If the item is an ActionManagerItem then the item is
+        appended to the manager's default group.
+        """
+
+    def destroy(self):
+        """ Called when the manager is no longer required.
+
+        By default this method simply calls 'destroy' on all of the manager's
+        groups.
+        """
+
+    def insert(self, index, item):
+        """ Insert an item into the manager at the specified index.
+
+        Parameters
+        ----------
+        index : int
+            The position at which to insert the object
+        item : string, Group instance or ActionManagerItem
+            The item to insert.
+
+        Notes
+        -----
+
+        If the item is a group, the Group is inserted into the manager's list
+        of groups.  It the item is a string, then a group is created with
+        the string as the ``id`` and the new group is inserted into the list
+        of groups.  If the item is an ActionManagerItem then the item is
+        inserted into the manager's defualt group.
+        """
+
+    def find_group(self, id):
+        """ Find a group with a specified Id.
+
+        Parameters
+        ----------
+        id : str
+            The id of the group to find.
+
+        Returns
+        -------
+        group : Group
+            The group which matches the id, or None if no such group exists.
+        """
+
+    def find_item(self, path):
+        """ Find an item using a path.
+
+        Parameters
+        ----------
+        path : str
+            A '/' separated list of contribution Ids.
+
+        Returns
+        -------
+        item : ActionManagerItem or None
+            Returns the matching ActionManagerItem, or None if any component
+            of the path is not found.
+        """
+
+    def walk(self, fn):
+        """ Walk the manager applying a function at every item.
+
+        The components are walked in pre-order.
+
+        Parameters
+        ----------
+        fn : Callable
+            A callable to apply to the tree of groups and items, starting with
+            the manager.
+        """
+
+    def walk_group(self, group, fn):
+        """ Walk a group applying a function at every item.
+
+        The components are walked in pre-order.
+
+        Parameters
+        ----------
+        group : Group
+            The group to walk.
+        fn : Callable
+            A callable to apply to the tree of groups and items.
+        """
+
+    def walk_item(self, item, fn):
+        """ Walk an item (may be a sub-menu manager remember!).
+
+        The components are walked in pre-order.
+
+        Parameters
+        ----------
+        item : item
+            The item to walk.  This may be a submenu or similar in addition to
+            simple Action items.
+        fn : Callable
+            A callable to apply to the tree of items and subgroups.
+        """
diff --git a/pyface/action/i_menu_bar_manager.py b/pyface/action/i_menu_bar_manager.py
new file mode 100644
index 000000000..7a23a7fb8
--- /dev/null
+++ b/pyface/action/i_menu_bar_manager.py
@@ -0,0 +1,33 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+
+""" The interface for a menu bar manager. """
+
+from pyface.action.i_action_manager import IActionManager
+
+
+class IMenuBarManager(IActionManager):
+    """ The interface for a menu bar manager. """
+
+    # ------------------------------------------------------------------------
+    # 'MenuBarManager' interface.
+    # ------------------------------------------------------------------------
+
+    def create_menu_bar(self, parent, controller=None):
+        """ Creates a menu bar representation of the manager.
+
+        Parameters
+        ----------
+        parent : toolkit control
+            The toolkit control that owns the menubar.
+        controller : pyface.action.action_controller.ActionController
+            An optional ActionController for all items in the menubar.
+        """
diff --git a/pyface/action/i_menu_manager.py b/pyface/action/i_menu_manager.py
new file mode 100644
index 000000000..cd1132562
--- /dev/null
+++ b/pyface/action/i_menu_manager.py
@@ -0,0 +1,45 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+from traits.api import Instance, Str
+
+from pyface.action.action import Action
+from pyface.action.i_action_manager import IActionManager
+
+
+class IMenuManager(IActionManager):
+    """ A menu manager realizes itself in a menu control.
+
+    This could be a sub-menu or a context (popup) menu.
+    """
+
+    # 'IMenuManager' interface ---------------------------------------------#
+
+    # The menu manager's name (if the manager is a sub-menu, this is what its
+    # label will be).
+    name = Str()
+
+    # The default action for tool button when shown in a toolbar (Qt only)
+    action = Instance(Action)
+
+    # ------------------------------------------------------------------------
+    # 'IMenuManager' interface.
+    # ------------------------------------------------------------------------
+
+    def create_menu(self, parent, controller=None):
+        """ Creates a menu representation of the manager.
+
+        Parameters
+        ----------
+        parent : toolkit control
+            The toolkit control that owns the menu.
+        controller : pyface.action.action_controller.ActionController
+            An optional ActionController for all items in the menu.
+        """
diff --git a/pyface/action/i_status_bar_manager.py b/pyface/action/i_status_bar_manager.py
new file mode 100644
index 000000000..c2d43def0
--- /dev/null
+++ b/pyface/action/i_status_bar_manager.py
@@ -0,0 +1,43 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+
+from traits.api import Any, Bool, Interface, List, Str
+
+
+class IStatusBarManager(Interface):
+    """ The interface for a status bar manager. """
+
+    # The message displayed in the first field of the status bar.
+    message = Str()
+
+    # The messages to be displayed in the status bar fields.
+    messages = List(Str)
+
+    # The toolkit-specific control that represents the status bar.
+    status_bar = Any()
+
+    # Whether to show a size grip on the status bar.
+    size_grip = Bool(False)
+
+    # Whether the status bar is visible.
+    visible = Bool(True)
+
+    def create_status_bar(self, parent):
+        """ Creates a status bar.
+
+        Parameters
+        ----------
+        parent : toolkit control
+            The toolkit control that owns the status bar.
+        """
+
+    def destroy(self):
+        """ Destroys the status bar. """
diff --git a/pyface/action/i_tool_bar_manager.py b/pyface/action/i_tool_bar_manager.py
new file mode 100644
index 000000000..08e536036
--- /dev/null
+++ b/pyface/action/i_tool_bar_manager.py
@@ -0,0 +1,50 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+from traits.api import Bool, Str, Tuple
+
+from pyface.action.i_action_manager import IActionManager
+from pyface.ui_traits import Orientation
+
+
+class IToolBarManager(IActionManager):
+    """ The interface for a tool bar manager. """
+
+    # 'IToolBarManager' interface -------------------------------------------
+
+    # The size of tool images (width, height).
+    image_size = Tuple((16, 16))
+
+    # The toolbar name (used to distinguish multiple toolbars).
+    name = Str("ToolBar")
+
+    # The orientation of the toolbar.
+    orientation = Orientation("horizontal")
+
+    # Should we display the name of each tool bar tool under its image?
+    show_tool_names = Bool(True)
+
+    # Should we display the horizontal divider?
+    show_divider = Bool(True)
+
+    # ------------------------------------------------------------------------
+    # 'ToolBarManager' interface.
+    # ------------------------------------------------------------------------
+
+    def create_tool_bar(self, parent, controller=None):
+        """ Creates a tool bar.
+
+        Parameters
+        ----------
+        parent : toolkit control
+            The toolkit control that owns the toolbar.
+        controller : pyface.action.action_controller.ActionController
+            An optional ActionController for all items in the toolbar.
+        """
diff --git a/pyface/action/tests/test_api.py b/pyface/action/tests/test_api.py
new file mode 100644
index 000000000..27523b7e2
--- /dev/null
+++ b/pyface/action/tests/test_api.py
@@ -0,0 +1,35 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" Test for pyface.api """
+
+import unittest
+
+
+class TestApi(unittest.TestCase):
+    """ Test importable items in any environment."""
+
+    def test_api_importable(self):
+        # make sure api is importable with the most minimal
+        # required dependencies, including in the absence of toolkit backends.
+        from pyface.action import api   # noqa: F401
+
+    def test_public_attrs(self):
+        # make sure everything advertised by dir() is available except optional
+        from pyface.action import api
+
+        attrs = [
+            name
+            for name in dir(api)
+            if not name.startswith('_')
+        ]
+        for attr in attrs:
+            with self.subTest(attr=attr):
+                self.assertIsNotNone(getattr(api, attr, None))
diff --git a/pyface/action/window_action.py b/pyface/action/window_action.py
index 7bfd4a1bd..73979bcdf 100644
--- a/pyface/action/window_action.py
+++ b/pyface/action/window_action.py
@@ -13,11 +13,10 @@
 """ Abstract base class for all window actions. """
 
 
-from pyface.window import Window
 from traits.api import Instance, Property
 
-
 from pyface.action.listening_action import ListeningAction
+from pyface.i_window import IWindow
 
 
 class WindowAction(ListeningAction):
@@ -30,7 +29,7 @@ class WindowAction(ListeningAction):
     # 'WindowAction' interface -----------------------------------------------
 
     #: The window that the action is associated with.
-    window = Instance(Window)
+    window = Instance(IWindow)
 
     # ------------------------------------------------------------------------
     # Protected interface.
diff --git a/pyface/api.py b/pyface/api.py
index 0ea18758b..2fbfa2e1c 100644
--- a/pyface/api.py
+++ b/pyface/api.py
@@ -16,6 +16,7 @@
 - :class:`~.ApplicationWindow`
 - :attr:`~.clipboard`
 - :class:`~.Clipboard`
+- :func:`~.find_toolkit`
 - :class:`~.GUI`
 - :class:`~.GUIApplication`
 - :class:`~.ImageResource`
@@ -24,6 +25,7 @@
 - :class:`~.SplitApplicationWindow`
 - :class:`~.SplitPanel`
 - :class:`~.SystemMetrics`
+- :class:`~.Toolkit`
 - :class:`~.Window`
 - :class:`~.Widget`
 
@@ -134,87 +136,15 @@
 
 """
 
-import logging as _logging
+# Imports which don't select the toolkit as a side-effect.
 
-from .about_dialog import AboutDialog
 from .application import Application
-from .application_window import ApplicationWindow
-from .beep import beep
-from .clipboard import clipboard, Clipboard
-from .confirmation_dialog import confirm, ConfirmationDialog
+from .base_toolkit import Toolkit, find_toolkit
 from .color import Color
 from .constant import OK, CANCEL, YES, NO
-from .dialog import Dialog
-from .directory_dialog import DirectoryDialog
-from .drop_handler import BaseDropHandler, FileDropHandler
-from .file_dialog import FileDialog
 from .filter import Filter
 from .font import Font
-from .gui import GUI
 from .gui_application import GUIApplication
-from .heading_text import HeadingText
-from .image_cache import ImageCache
-from .image_resource import ImageResource
-from .key_pressed_event import KeyPressedEvent
-from .layered_panel import LayeredPanel
-from .message_dialog import error, information, warning, MessageDialog
-from .progress_dialog import ProgressDialog
-
-from .util._optional_dependencies import optional_import as _optional_import
-
-# Excuse numpy dependency, otherwise re-raise
-with _optional_import(
-        "numpy",
-        msg="ArrayImage not available due to missing numpy.",
-        logger=_logging.getLogger(__name__)):
-
-    # We need to manually try importing numpy because the ``ArrayImage``
-    # import will end up raising a ``TraitError`` exception instead of an
-    # ``ImportError``, which isnt caught by ``_optional_import``.
-    import numpy
-
-    from .array_image import ArrayImage
-
-    del numpy
-
-# Excuse pillow dependency, otherwise re-raise
-with _optional_import(
-        "pillow",
-        msg="PILImage not available due to missing pillow.",
-        logger=_logging.getLogger(__name__)):
-    from .pil_image import PILImage
-
-# Excuse pygments dependency (for Qt), otherwise re-raise
-with _optional_import(
-        "pygments",
-        msg="PythonEditor not available due to missing pygments.",
-        logger=_logging.getLogger(__name__)):
-    from .python_editor import PythonEditor
-
-with _optional_import(
-        "pygments",
-        msg="PythonShell not available due to missing pygments.",
-        logger=_logging.getLogger(__name__)):
-    from .python_shell import PythonShell
-
-from .sorter import Sorter
-from .single_choice_dialog import choose_one, SingleChoiceDialog
-from .splash_screen import SplashScreen
-from .split_application_window import SplitApplicationWindow
-from .split_dialog import SplitDialog
-from .split_panel import SplitPanel
-from .system_metrics import SystemMetrics
-from .ui_traits import (
-    Alignment, Border, HasBorder, HasMargin, Image, Margin, Orientation,
-    Position, PyfaceColor, PyfaceFont
-)
-from .window import Window
-from .widget import Widget
-
-# ----------------------------------------------------------------------------
-# Public Interfaces
-# ----------------------------------------------------------------------------
-
 from .i_about_dialog import IAboutDialog
 from .i_application_window import IApplicationWindow
 from .i_clipboard import IClipboard
@@ -241,27 +171,122 @@
 from .i_system_metrics import ISystemMetrics
 from .i_widget import IWidget
 from .i_window import IWindow
+from .sorter import Sorter
+from .ui_traits import (
+    Alignment, Border, HasBorder, HasMargin, Image, Margin, Orientation,
+    Position, PyfaceColor, PyfaceFont
+)
 
 # ----------------------------------------------------------------------------
-# Legacy and Wx-specific imports.
+# Deferred imports
 # ----------------------------------------------------------------------------
 
-# These widgets currently only have Wx implementations
-# will return Unimplemented for Qt.
+# These imports have the side-effect of performing toolkit selection
+
+_toolkit_imports = {
+    'AboutDialog': 'about_dialog',
+    'ApplicationWindow': "application_window",
+    'BaseDropHandler': "drop_handler",
+    'beep': "beep",
+    'Clipboard': "clipboard",
+    'ConfirmationDialog': "confirmation_dialog",
+    'Dialog': "dialog",
+    'DirectoryDialog': "directory_dialog",
+    'FileDropHandler': "drop_handler",
+    'FileDialog': "file_dialog",
+    'GUI': 'gui',
+    'HeadingText': "heading_text",
+    'ImageCache': "image_cache",
+    'ImageResource': "image_resource",
+    'KeyPressedEvent': "key_pressed_event",
+    'LayeredPanel': "layered_panel",
+    'MessageDialog': "message_dialog",
+    'ProgressDialog': "progress_dialog",
+    'SingleChoiceDialog': "single_choice_dialog",
+    'SplashScreen': "splash_screen",
+    'SystemMetrics': "system_metrics",
+    'Window': "window",
+    'Widget': "widget",
+
+    # Wx-only (or legacy) imports
+    'ExpandablePanel': "expandable_panel",
+    'ImageWidget': "image_widget",
+    'MDIApplicationWindow': "mdi_application_window",
+    'MDIWindowMenu': "mdi_window_menu",
+    'MultiToolbarWindow': "multi_toolbar_window",
+}
+
+# These are pyface.* imports that have selection as a side-effect
+# TODO: refactor to delay imports where possible
+_relative_imports = {
+    'choose_one': "single_choice_dialog",
+    'clipboard': "clipboard",
+    'confirm': "confirmation_dialog",
+    'error': "message_dialog",
+    'information': "message_dialog",
+    'SplitApplicationWindow': "split_application_window",
+    'SplitDialog': "split_dialog",
+    'SplitPanel': "split_panel",
+    'warning': "message_dialog",
+}
+_optional_imports = {
+    'ArrayImage': ("numpy", "array_image"),
+    'PILImage': ("pillow", "pil_image"),
+    'PythonEditor': ("pygments", "python_editor"),
+    'PythonShell': ("pygments", "python_shell"),
+}
+
+
+def __getattr__(name):
+    """Lazily load attributes with side-effects
+
+    In particular, lazily load toolkit backend names.  For efficiency, lazily
+    loaded objects are injected into the module namespace
+    """
+    # sentinel object for no result
+    not_found = object()
+    result = not_found
+
+    if name in _relative_imports:
+        from importlib import import_module
+        source = _relative_imports[name]
+        module = import_module(f"pyface.{source}")
+        result = getattr(module, name)
+
+    elif name in _toolkit_imports:
+        from pyface.toolkit import toolkit_object
+        source = _toolkit_imports[name]
+        result = toolkit_object(f"{source}:{name}")
+
+    elif name in _optional_imports:
+        from importlib import import_module
+        import logging
+        from pyface.util._optional_dependencies import optional_import
+        dependency, source = _optional_imports[name]
+        with optional_import(
+            dependency,
+            msg=f"{name} is not available due to missing {dependency}.",
+            logger=logging.getLogger(__name__),
+        ):
+            module = import_module(f"pyface.{source}")
+            result = getattr(module, name)
+
+    if result is not_found:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+    globals()[name] = result
+    return result
 
-from .expandable_panel import ExpandablePanel
-from .image_widget import ImageWidget
-from .mdi_application_window import MDIApplicationWindow
-from .mdi_window_menu import MDIWindowMenu
-from .multi_toolbar_window import MultiToolbarWindow
 
-# This code isn't toolkit widget code, but is wx-specific
-from traits.etsconfig.api import ETSConfig
+# ----------------------------------------------------------------------------
+# Introspection support
+# ----------------------------------------------------------------------------
 
-if ETSConfig.toolkit == "wx":
+# the list of available names we report for introspection purposes
+_extra_names = (
+    set(_toolkit_imports) | set(_relative_imports) | set(_optional_imports)
+)
 
-    # Fix for broken Pycrust introspect module.
-    # XXX move this somewhere better? - CJW 2017
-    from .util import fix_introspect_bug
 
-del ETSConfig
+def __dir__():
+    return sorted(set(globals()) | _extra_names)
diff --git a/pyface/base_toolkit.py b/pyface/base_toolkit.py
index ad53b1591..0bc1fff9b 100644
--- a/pyface/base_toolkit.py
+++ b/pyface/base_toolkit.py
@@ -179,7 +179,7 @@ def import_toolkit(toolkit_name, entry_point="pyface.toolkits"):
 
     Returns
     -------
-    toolkit_object : callable
+    toolkit_object : Callable
         A callable object that implements the Toolkit interface.
 
     Raises
@@ -231,7 +231,11 @@ def import_toolkit(toolkit_name, entry_point="pyface.toolkits"):
     raise RuntimeError(msg) from toolkit_exception
 
 
-def find_toolkit(entry_point, toolkits=None, priorities=default_priorities):
+def find_toolkit(
+    entry_point="pyface.toolkits",
+    toolkits=None,
+    priorities=default_priorities,
+):
     """ Find a toolkit that works.
 
     If ETSConfig is set, then attempt to find a matching toolkit.  Otherwise
@@ -247,12 +251,12 @@ def find_toolkit(entry_point, toolkits=None, priorities=default_priorities):
     toolkits : collection of strings
         Only consider toolkits which match the given strings, ignore other
         ones.
-    priorities : callable
+    priorities : Callable
         A callable function that returns an priority for each plugin.
 
     Returns
     -------
-    toolkit : Toolkit instance
+    toolkit : Toolkit
         A callable object that implements the Toolkit interface.
 
     Raises
diff --git a/pyface/data_view/abstract_data_exporter.py b/pyface/data_view/abstract_data_exporter.py
index 8602cfad6..6d1e31d44 100644
--- a/pyface/data_view/abstract_data_exporter.py
+++ b/pyface/data_view/abstract_data_exporter.py
@@ -36,9 +36,9 @@ def add_data(self, data_wrapper, model, indices):
 
         Parameters
         ----------
-        data_wrapper : DataWrapper instance
+        data_wrapper : DataWrapper
             The data wrapper that will be used to export data.
-        model : AbstractDataModel instance
+        model : AbstractDataModel
             The data model holding the data.
         indices : list of (row, column) index pairs
             The indices where the data is to be stored.
@@ -55,14 +55,14 @@ def get_data(self, model, indices):
 
         Parameters
         ----------
-        model : AbstractDataModel instance
+        model : AbstractDataModel
             The data model holding the data.
         indices : list of (row, column) index pairs
             The indices where the data is to be stored.
 
         Returns
         -------
-        data : any
+        data : Any
             The data, of a type that can be serialized by the format.
         """
         raise NotImplementedError()
diff --git a/pyface/data_view/abstract_data_model.py b/pyface/data_view/abstract_data_model.py
index 6a6d10aac..2690ad861 100644
--- a/pyface/data_view/abstract_data_model.py
+++ b/pyface/data_view/abstract_data_model.py
@@ -150,7 +150,7 @@ def get_value(self, row, column):
 
         Returns
         -------
-        value : any
+        value : Any
             The value represented by the given row and column.
 
         Raises
@@ -202,7 +202,7 @@ def set_value(self, row, column, value):
             The indices of the row as a sequence from root to leaf.
         column : sequence of int
             The indices of the column as a sequence of length 0 or 1.
-        value : any
+        value : Any
             The new value for the given row and column.
 
         Raises
diff --git a/pyface/data_view/abstract_value_type.py b/pyface/data_view/abstract_value_type.py
index 47cd23640..697007f8f 100644
--- a/pyface/data_view/abstract_value_type.py
+++ b/pyface/data_view/abstract_value_type.py
@@ -94,7 +94,7 @@ def get_editor_value(self, model, row, column):
 
         Returns
         -------
-        value : any
+        value : Any
             The value to edit.
         """
         return model.get_value(row, column)
@@ -113,7 +113,7 @@ def set_editor_value(self, model, row, column, value):
             The row in the data model being queried.
         column : sequence of int
             The column in the data model being queried.
-        value : any
+        value : Any
             The value to set.
 
         Raises
@@ -228,7 +228,7 @@ def get_color(self, model, row, column):
 
         Returns
         -------
-        color : Color instance
+        color : Color
             The color associated with the cell.
         """
         return Color(rgba=(1.0, 1.0, 1.0, 1.0))
diff --git a/pyface/data_view/api.py b/pyface/data_view/api.py
index 7d19218cc..e4ef206e3 100644
--- a/pyface/data_view/api.py
+++ b/pyface/data_view/api.py
@@ -65,24 +65,64 @@
 
 """
 
-from pyface.data_view.abstract_data_exporter import AbstractDataExporter  # noqa: 401
-from pyface.data_view.abstract_data_model import AbstractDataModel  # noqa: 401
-from pyface.data_view.abstract_value_type import AbstractValueType  # noqa: 401
-from pyface.data_view.data_formats import (  # noqa: 401
+from pyface.data_view.abstract_data_exporter import AbstractDataExporter
+from pyface.data_view.abstract_data_model import AbstractDataModel
+from pyface.data_view.abstract_value_type import AbstractValueType
+from pyface.data_view.data_formats import (
     csv_column_format, csv_format, csv_row_format, from_csv, from_csv_column,
     from_csv_row, from_json, from_npy, html_format, npy_format,
     standard_text_format, to_csv, to_csv_column, to_csv_row, to_json, to_npy,
     table_format, text_column_format, text_row_format
 )
-from pyface.data_view.data_view_errors import (  # noqa: 401
+from pyface.data_view.data_view_errors import (
     DataViewError, DataViewGetError, DataViewSetError
 )
-from pyface.data_view.data_view_widget import DataViewWidget  # noqa: 401
-from pyface.data_view.data_wrapper import DataWrapper  # noqa: 401
-from pyface.data_view.i_data_view_widget import IDataViewWidget  # noqa: 401
-from pyface.data_view.i_data_wrapper import (  # noqa: 401
+from pyface.data_view.i_data_view_widget import IDataViewWidget
+from pyface.data_view.i_data_wrapper import (
     DataFormat, IDataWrapper, text_format
 )
-from pyface.data_view.index_manager import (  # noqa: 401
+from pyface.data_view.index_manager import (
     AbstractIndexManager, IntIndexManager, TupleIndexManager
 )
+
+
+# ----------------------------------------------------------------------------
+# Deferred imports
+# ----------------------------------------------------------------------------
+
+# These imports have the side-effect of performing toolkit selection
+
+_toolkit_imports = {
+    'DataViewWidget': 'data_view_widget',
+    'DataWrapper': 'data_wrapper',
+}
+
+
+def __getattr__(name):
+    """Lazily load attributes with side-effects
+
+    In particular, lazily load toolkit backend names.  For efficiency, lazily
+    loaded objects are injected into the module namespace
+    """
+    # sentinel object for no result
+    not_found = object()
+    result = not_found
+
+    if name in _toolkit_imports:
+        from pyface.toolkit import toolkit_object
+        source = _toolkit_imports[name]
+        result = toolkit_object(f"data_view.{source}:{name}")
+
+    if result is not_found:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+    globals()[name] = result
+    return result
+
+
+# ----------------------------------------------------------------------------
+# Introspection support
+# ----------------------------------------------------------------------------
+
+def __dir__():
+    return sorted(set(globals()) | set(_toolkit_imports))
diff --git a/pyface/data_view/data_formats.py b/pyface/data_view/data_formats.py
index e2f1f0d69..a5f315404 100644
--- a/pyface/data_view/data_formats.py
+++ b/pyface/data_view/data_formats.py
@@ -23,9 +23,9 @@ def to_json(data, default=None):
 
     Parameters
     ----------
-    data : any
+    data : Any
         The data to be serialized.
-    default : callable or None
+    default : Callable or None
         Callable that takes a Python object and returns a JSON-serializable
         data structure.
 
@@ -45,13 +45,13 @@ def from_json(raw_data, object_hook=None):
     ----------
     raw_data : bytes
         The serialized JSON data as a byte string.
-    object_hook : callable
+    object_hook : Callable
         Callable that takes a dictionary and returns an corresponding
         Python object.
 
     Returns
     -------
-    data : any
+    data : Any
         The data extracted.
     """
     return json.loads(raw_data.decode('utf-8'), object_hook=object_hook)
diff --git a/pyface/data_view/data_models/array_data_model.py b/pyface/data_view/data_models/array_data_model.py
index dce74f47a..3b48afd72 100644
--- a/pyface/data_view/data_models/array_data_model.py
+++ b/pyface/data_view/data_models/array_data_model.py
@@ -205,7 +205,7 @@ def set_value(self, row, column, value):
 
         Returns
         -------
-        value : any
+        value : Any
             The value represented by the given row and column.
         """
         if self.can_set_value(row, column):
diff --git a/pyface/data_view/data_models/data_accessors.py b/pyface/data_view/data_models/data_accessors.py
index cb23ee0da..4b375c40e 100644
--- a/pyface/data_view/data_models/data_accessors.py
+++ b/pyface/data_view/data_models/data_accessors.py
@@ -52,12 +52,12 @@ def get_value(self, obj):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             The object that contains the data.
 
         Returns
         -------
-        value : any
+        value : Any
             The data value contained in the object.
         """
         raise NotImplementedError()
@@ -67,7 +67,7 @@ def can_set_value(self, obj):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             The object that contains the data.
 
         Returns
@@ -82,9 +82,9 @@ def set_value(self, obj, value):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             The object that contains the data.
-        value : any
+        value : Any
             The data value to set.
 
         Raises
@@ -119,12 +119,12 @@ def get_value(self, obj):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             An object.
 
         Returns
         -------
-        value : any
+        value : Any
             The data value contained in this class' value trait.
         """
         return self.value
@@ -149,12 +149,12 @@ def get_value(self, obj):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             The object that contains the data.
 
         Returns
         -------
-        value : any
+        value : Any
             The data value contained in the object's attribute.
         """
         return xgetattr(obj, self.attr)
@@ -164,7 +164,7 @@ def can_set_value(self, obj):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             The object that contains the data.
 
         Returns
@@ -211,7 +211,7 @@ def get_value(self, obj):
 
         Returns
         -------
-        value : any
+        value : Any
             The data value contained in the object at the index.
         """
         return obj[self.index]
@@ -221,7 +221,7 @@ def can_set_value(self, obj):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             The object that contains the data.
 
         Returns
@@ -236,9 +236,9 @@ def set_value(self, obj, value):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             The object that contains the data.
-        value : any
+        value : Any
             The data value to set.
 
         Raises
@@ -280,7 +280,7 @@ def get_value(self, obj):
 
         Returns
         -------
-        value : any
+        value : Any
             The data value contained in the given key of the object.
         """
         return obj[self.key]
@@ -292,7 +292,7 @@ def can_set_value(self, obj):
         ----------
         obj : mapping
             The object that contains the data.
-        value : any
+        value : Any
             The data value to set.
 
         Raises
@@ -307,9 +307,9 @@ def set_value(self, obj, value):
 
         Parameters
         ----------
-        obj : any
+        obj : Any
             The object that contains the data.
-        value : any
+        value : Any
             The data value to set.
 
         Raises
diff --git a/pyface/data_view/data_models/row_table_data_model.py b/pyface/data_view/data_models/row_table_data_model.py
index e9abf39eb..f9899055e 100644
--- a/pyface/data_view/data_models/row_table_data_model.py
+++ b/pyface/data_view/data_models/row_table_data_model.py
@@ -111,7 +111,7 @@ def get_value(self, row, column):
 
         Returns
         -------
-        value : any
+        value : Any
             The value represented by the given row and column.
         """
         if len(column) == 0:
@@ -162,7 +162,7 @@ def set_value(self, row, column, value):
             The indices of the row as a sequence from root to leaf.
         column : sequence of int
             The indices of the column as a sequence of length 0 or 1.
-        value : any
+        value : Any
             The new value for the given row and column.
 
         Raises
diff --git a/pyface/data_view/exporters/item_exporter.py b/pyface/data_view/exporters/item_exporter.py
index 12b5bf2ec..d648afdd7 100644
--- a/pyface/data_view/exporters/item_exporter.py
+++ b/pyface/data_view/exporters/item_exporter.py
@@ -26,9 +26,9 @@ def add_data(self, data_wrapper, model, indices):
 
         Parameters
         ----------
-        data_wrapper : DataWrapper instance
+        data_wrapper : DataWrapper
             The data wrapper that will be used to export data.
-        model : AbstractDataModel instance
+        model : AbstractDataModel
             The data model holding the data.
         indices : list of (row, column) index pairs
             The indices where the data is to be stored.
@@ -42,14 +42,14 @@ def get_data(self, model, indices):
 
         Parameters
         ----------
-        model : AbstractDataModel instance
+        model : AbstractDataModel
             The data model holding the data.
         indices : list of (row, column) index pairs
             The indices where the data is to be stored.
 
         Returns
         -------
-        data : any
+        data : Any
             The data, of a type that can be serialized by the format.
         """
         if len(indices) != 1:
diff --git a/pyface/data_view/exporters/row_exporter.py b/pyface/data_view/exporters/row_exporter.py
index f5cd9accb..e1bcd8e95 100644
--- a/pyface/data_view/exporters/row_exporter.py
+++ b/pyface/data_view/exporters/row_exporter.py
@@ -44,14 +44,14 @@ def get_data(self, model, indices):
 
         Parameters
         ----------
-        model : AbstractDataModel instance
+        model : AbstractDataModel
             The data model holding the data.
         indices : list of (row, column) index pairs
             The indices where the data is to be stored.
 
         Returns
         -------
-        data : any
+        data : Any
             The data, of a type that can be serialized by the format.
         """
         rows = sorted({row for row, column in indices})
diff --git a/pyface/data_view/i_data_wrapper.py b/pyface/data_view/i_data_wrapper.py
index 5152a95ed..ed5bba885 100644
--- a/pyface/data_view/i_data_wrapper.py
+++ b/pyface/data_view/i_data_wrapper.py
@@ -93,7 +93,7 @@ def get_format(self, format):
 
         Returns
         -------
-        data : any
+        data : Any
             The data decoded for the given format.
         """
         raise NotImplementedError()
@@ -105,7 +105,7 @@ def set_format(self, format, data):
         ----------
         format : DataFormat
             A data format object.
-        data : any
+        data : Any
             The data to be encoded and stored.
         """
         raise NotImplementedError()
@@ -171,7 +171,7 @@ def get_format(self, format):
 
         Returns
         -------
-        data : any
+        data : Any
             The data decoded for the given format.
         """
         return format.deserialize(self.get_mimedata(format.mimetype))
@@ -183,7 +183,7 @@ def set_format(self, format, data):
         ----------
         format : DataFormat
             A data format object.
-        data : any
+        data : Any
             The data to be encoded and stored.
         """
         self.set_mimedata(format.mimetype, format.serialize(data))
diff --git a/pyface/data_view/value_types/color_value.py b/pyface/data_view/value_types/color_value.py
index e8f4dae12..900500c44 100644
--- a/pyface/data_view/value_types/color_value.py
+++ b/pyface/data_view/value_types/color_value.py
@@ -34,7 +34,7 @@ def is_valid(self, model, row, column, value):
             The row in the data model being queried.
         column : sequence of int
             The column in the data model being queried.
-        value : any
+        value : Any
             The value to test.
 
         Returns
@@ -168,7 +168,7 @@ def get_color(self, model, row, column):
 
         Returns
         -------
-        color : Color instance
+        color : Color
             The color associated with the cell.
         """
         return model.get_value(row, column)
diff --git a/pyface/data_view/value_types/constant_value.py b/pyface/data_view/value_types/constant_value.py
index 855a24e95..1d6bc4133 100644
--- a/pyface/data_view/value_types/constant_value.py
+++ b/pyface/data_view/value_types/constant_value.py
@@ -79,7 +79,7 @@ def get_color(self, model, row, column):
 
         Returns
         -------
-        color : Color instance
+        color : Color
             The color associated with the cell.
         """
         return self.color
diff --git a/pyface/data_view/value_types/editable_value.py b/pyface/data_view/value_types/editable_value.py
index 918cdf961..f03b29425 100644
--- a/pyface/data_view/value_types/editable_value.py
+++ b/pyface/data_view/value_types/editable_value.py
@@ -40,7 +40,7 @@ def is_valid(self, model, row, column, value):
             The row in the data model being queried.
         column : sequence of int
             The column in the data model being queried.
-        value : any
+        value : Any
             The value to validate.
 
         Returns
@@ -85,7 +85,7 @@ def set_editor_value(self, model, row, column, value):
             The row in the data model being set.
         column : sequence of int
             The column in the data model being set.
-        value : any
+        value : Any
             The value being set.
 
         Raises
diff --git a/pyface/data_view/value_types/enum_value.py b/pyface/data_view/value_types/enum_value.py
index 45a634347..3ff260ab2 100644
--- a/pyface/data_view/value_types/enum_value.py
+++ b/pyface/data_view/value_types/enum_value.py
@@ -43,7 +43,7 @@ def is_valid(self, model, row, column, value):
             The row in the data model being queried.
         column : sequence of int
             The column in the data model being queried.
-        value : any
+        value : Any
             The value to validate.
 
         Returns
@@ -127,7 +127,7 @@ def get_color(self, model, row, column):
 
         Returns
         -------
-        color : Color instance
+        color : Color
             The color associated with the cell.
         """
         return self.colors(model.get_value(row, column))
diff --git a/pyface/data_view/value_types/numeric_value.py b/pyface/data_view/value_types/numeric_value.py
index 447f0e989..b13d46317 100644
--- a/pyface/data_view/value_types/numeric_value.py
+++ b/pyface/data_view/value_types/numeric_value.py
@@ -51,7 +51,7 @@ def is_valid(self, model, row, column, value):
             The row in the data model being queried.
         column : sequence of int
             The column in the data model being queried.
-        value : any
+        value : Any
             The value to validate.
 
         Returns
diff --git a/pyface/dock/dock_window_feature.py b/pyface/dock/dock_window_feature.py
index 82f5a6528..34fff4500 100644
--- a/pyface/dock/dock_window_feature.py
+++ b/pyface/dock/dock_window_feature.py
@@ -302,7 +302,7 @@ def drop(self, object):
 
         Parameters
         ----------
-        object : any object
+        object : Any object
             The object being dropped onto the feature image
 
         Returns
@@ -329,7 +329,7 @@ def can_drop(self, object):
 
         Parameters
         ----------
-        object : any object
+        object : Any object
             The object being dragged onto the feature image
 
         Returns
diff --git a/pyface/fields/api.py b/pyface/fields/api.py
index eebe2c632..4287c9038 100644
--- a/pyface/fields/api.py
+++ b/pyface/fields/api.py
@@ -14,6 +14,10 @@
 
 - :class:`~.CheckBoxField`
 - :class:`~.ComboField`
+- :class:`~.EditableField`
+- :class:`~.Field`
+- :class:`~.ImageField`
+- :class:`~.LabelField`
 - :class:`~.RadioButtonField`
 - :class:`~.SpinField`
 - :class:`~.TextField`
@@ -23,7 +27,10 @@
 Interfaces
 ----------
 - :class:`~.IComboField`
+- :class:`~.IEditableField`
 - :class:`~.IField`
+- :class:`~.IImageField`
+- :class:`~.ILabelField`
 - :class:`~.ISpinField`
 - :class:`~.ITextField`
 - :class:`~.ITimeField`
@@ -32,16 +39,62 @@
 """
 
 from .i_combo_field import IComboField
+from .i_editable_field import IEditableField
 from .i_field import IField
+from .i_image_field import IImageField
+from .i_label_field import ILabelField
 from .i_spin_field import ISpinField
 from .i_text_field import ITextField
 from .i_time_field import ITimeField
 from .i_toggle_field import IToggleField
 
-from .combo_field import ComboField
-from .spin_field import SpinField
-from .text_field import TextField
-from .time_field import TimeField
-from .toggle_field import (
-    CheckBoxField, RadioButtonField, ToggleButtonField,
-)
+
+# ----------------------------------------------------------------------------
+# Deferred imports
+# ----------------------------------------------------------------------------
+
+# These imports have the side-effect of performing toolkit selection
+
+_toolkit_imports = {
+    'CheckBoxField': 'toggle_field',
+    'ComboField': 'combo_field',
+    'EditableField': 'editable_field',
+    'Field': 'field',
+    'ImageField': 'image_field',
+    'LabelField': 'label_field',
+    'RadioButtonField': 'toggle_field',
+    'SpinField': 'spin_field',
+    'TextField': 'text_field',
+    'TimeField': 'time_field',
+    'ToggleButtonField': 'toggle_field',
+}
+
+
+def __getattr__(name):
+    """Lazily load attributes with side-effects
+
+    In particular, lazily load toolkit backend names.  For efficiency, lazily
+    loaded objects are injected into the module namespace
+    """
+    # sentinel object for no result
+    not_found = object()
+    result = not_found
+
+    if name in _toolkit_imports:
+        from pyface.toolkit import toolkit_object
+        source = _toolkit_imports[name]
+        result = toolkit_object(f"fields.{source}:{name}")
+
+    if result is not_found:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+    globals()[name] = result
+    return result
+
+
+# ----------------------------------------------------------------------------
+# Introspection support
+# ----------------------------------------------------------------------------
+
+def __dir__():
+    return sorted(set(globals()) | set(_toolkit_imports))
diff --git a/pyface/fields/i_combo_field.py b/pyface/fields/i_combo_field.py
index 2220b85c7..18839fafd 100644
--- a/pyface/fields/i_combo_field.py
+++ b/pyface/fields/i_combo_field.py
@@ -13,10 +13,10 @@
 
 from traits.api import Callable, HasTraits, Enum, List
 
-from pyface.fields.i_field import IField
+from pyface.fields.i_editable_field import IEditableField
 
 
-class IComboField(IField):
+class IComboField(IEditableField):
     """ The combo field interface.
 
     This is for comboboxes holding a list of values.
@@ -64,7 +64,6 @@ def __init__(self, values, **traits):
     def _initialize_control(self):
         super()._initialize_control()
         self._set_control_values(self.values)
-        self._set_control_value(self.value)
 
     def _add_event_listeners(self):
         """ Set up toolkit-specific bindings for events """
@@ -72,13 +71,9 @@ def _add_event_listeners(self):
         self.observe(
             self._values_updated, "values.items,formatter", dispatch="ui"
         )
-        if self.control is not None:
-            self._observe_control_value()
 
     def _remove_event_listeners(self):
         """ Remove toolkit-specific bindings for events """
-        if self.control is not None:
-            self._observe_control_value(remove=True)
         self.observe(
             self._values_updated,
             "values.items,formatter",
diff --git a/pyface/fields/i_editable_field.py b/pyface/fields/i_editable_field.py
new file mode 100644
index 000000000..6e28bb14e
--- /dev/null
+++ b/pyface/fields/i_editable_field.py
@@ -0,0 +1,62 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The editable field interface. """
+
+
+from traits.api import HasTraits
+
+from .i_field import IField
+
+
+class IEditableField(IField):
+    """ The editable field interface.
+
+    A editable field is a widget that displays a user-editable value.
+    """
+
+
+class MEditableField(HasTraits):
+    """The editable field mix-in.
+
+    Classes which use this mixin should implement _observe_control_value to
+    connect a toolkit handler that calls _update_value.
+    """
+
+    # ------------------------------------------------------------------------
+    # IWidget interface
+    # ------------------------------------------------------------------------
+
+    def _add_event_listeners(self):
+        """ Set up toolkit-specific bindings for events """
+        super()._add_event_listeners()
+        self._observe_control_value()
+
+    def _remove_event_listeners(self):
+        """ Remove toolkit-specific bindings for events """
+        self._observe_control_value(remove=True)
+        super()._remove_event_listeners()
+
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    def _update_value(self, value):
+        """ Handle a change to the value from user interaction
+
+        This is a method suitable for calling from a toolkit event handler.
+        """
+        self.value = self._get_control_value()
+
+    # Toolkit control interface ---------------------------------------------
+
+    def _observe_control_value(self, remove=False):
+        """ Toolkit specific method to change the control value observer. """
+        raise NotImplementedError()
diff --git a/pyface/fields/i_field.py b/pyface/fields/i_field.py
index 4380bf1d4..06e029110 100644
--- a/pyface/fields/i_field.py
+++ b/pyface/fields/i_field.py
@@ -14,6 +14,7 @@
 from traits.api import Any, HasTraits
 
 from pyface.i_layout_widget import ILayoutWidget
+from pyface.ui_traits import Alignment
 
 
 class IField(ILayoutWidget):
@@ -26,6 +27,9 @@ class IField(ILayoutWidget):
     #: The value held by the field.
     value = Any()
 
+    #: The alignment of the field's content.
+    alignment = Alignment()
+
 
 class MField(HasTraits):
     """ The field mix-in. """
@@ -33,44 +37,52 @@ class MField(HasTraits):
     #: The value held by the field.
     value = Any()
 
+    #: The alignment of the text in the field.
+    alignment = Alignment()
+
     # ------------------------------------------------------------------------
     # IWidget interface
     # ------------------------------------------------------------------------
 
+    def create(self, parent=None):
+        """ Creates the toolkit specific control.
+
+        This method should create the control and assign it to the
+        :py:attr:``control`` trait.
+        """
+        super().create(parent=parent)
+
+        self.show(self.visible)
+        self.enable(self.enabled)
+
+    def _initialize_control(self):
+        """ Perform any post-creation initialization for the control.
+        """
+        super()._initialize_control()
+        self._set_control_value(self.value)
+        if self.alignment != 'default':
+            self._set_control_alignment(self.alignment)
+
     def _add_event_listeners(self):
         """ Set up toolkit-specific bindings for events """
         super()._add_event_listeners()
         self.observe(self._value_updated, "value", dispatch="ui")
+        self.observe(self._alignment_updated, "alignment", dispatch="ui")
 
     def _remove_event_listeners(self):
         """ Remove toolkit-specific bindings for events """
         self.observe(
             self._value_updated, "value", dispatch="ui", remove=True
         )
+        self.observe(
+            self._alignment_updated, "alignment", dispatch="ui", remove=True
+        )
         super()._remove_event_listeners()
 
     # ------------------------------------------------------------------------
     # Private interface
     # ------------------------------------------------------------------------
 
-    def create(self, parent=None):
-        """ Creates the toolkit specific control.
-
-        This method should create the control and assign it to the
-        :py:attr:``control`` trait.
-        """
-        super().create(parent=parent)
-
-        self.show(self.visible)
-        self.enable(self.enabled)
-
-    def _update_value(self, value):
-        """ Handle a change to the value from user interaction
-
-        This is a method suitable for calling from a toolkit event handler.
-        """
-        self.value = self._get_control_value()
-
     def _get_control(self):
         """ If control is not passed directly, get it from the trait. """
         control = self.control
@@ -88,8 +100,12 @@ def _set_control_value(self, value):
         """ Toolkit specific method to set the control's value. """
         raise NotImplementedError()
 
-    def _observe_control_value(self, remove=False):
-        """ Toolkit specific method to change the control value observer. """
+    def _get_control_alignment(self):
+        """ Toolkit specific method to get the control's read_only state. """
+        raise NotImplementedError()
+
+    def _set_control_alignment(self, alignment):
+        """ Toolkit specific method to set the control's alignment. """
         raise NotImplementedError()
 
     # Trait change handlers -------------------------------------------------
@@ -98,3 +114,8 @@ def _value_updated(self, event):
         value = event.new
         if self.control is not None:
             self._set_control_value(value)
+
+    def _alignment_updated(self, event):
+        alignment = event.new
+        if self.control is not None:
+            self._set_control_alignment(alignment)
diff --git a/pyface/fields/i_image_field.py b/pyface/fields/i_image_field.py
new file mode 100644
index 000000000..3e45509fb
--- /dev/null
+++ b/pyface/fields/i_image_field.py
@@ -0,0 +1,36 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The image field interface. """
+
+from traits.api import Any, HasTraits
+
+from pyface.fields.i_field import IField
+from pyface.ui_traits import Image
+
+
+class IImageField(IField):
+    """ The image field interface.
+
+    This is for a field that edits a IImage value.
+    """
+
+    #: The current value of the image field
+    value = Image()
+
+
+class MImageField(HasTraits):
+    """ Mixin class for ImageField implementations """
+
+    #: The current value of the image field
+    value = Image()
+
+    #: The toolkit image to display
+    _toolkit_value = Any()
diff --git a/pyface/fields/i_label_field.py b/pyface/fields/i_label_field.py
new file mode 100644
index 000000000..437145917
--- /dev/null
+++ b/pyface/fields/i_label_field.py
@@ -0,0 +1,67 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The label field interface. """
+
+
+from traits.api import HasTraits, Str
+
+from pyface.fields.i_field import IField
+from pyface.ui_traits import Image
+
+
+class ILabelField(IField):
+    """ The label field interface. """
+
+    #: The value held by the field.
+    value = Str()
+
+    #: The icon to display with the toggle.
+    icon = Image()
+
+
+class MLabelField(HasTraits):
+    """ The text field mix-in. """
+
+    #: The value held by the field.
+    value = Str()
+
+    #: The icon to display with the toggle.
+    icon = Image()
+
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    def _initialize_control(self):
+        super()._initialize_control()
+        self._set_control_icon(self.icon)
+
+    def _add_event_listeners(self):
+        """ Set up toolkit-specific bindings for events """
+        super()._add_event_listeners()
+        self.observe(self._icon_updated, "icon", dispatch="ui")
+
+    def _remove_event_listeners(self):
+        """ Remove toolkit-specific bindings for events """
+        self.observe(self._icon_updated, "icon", dispatch="ui", remove=True)
+        super()._remove_event_listeners()
+
+    # Toolkit control interface ---------------------------------------------
+
+    def _set_control_icon(self, icon):
+        """ Toolkit specific method to set the control's icon. """
+        raise NotImplementedError()
+
+    # Trait change handlers -------------------------------------------------
+
+    def _icon_updated(self, event):
+        if self.control is not None:
+            self._set_control_icon(self.icon)
diff --git a/pyface/fields/i_spin_field.py b/pyface/fields/i_spin_field.py
index 37127e4a4..35d9e43ad 100644
--- a/pyface/fields/i_spin_field.py
+++ b/pyface/fields/i_spin_field.py
@@ -11,12 +11,12 @@
 """ The spin field interface. """
 
 
-from traits.api import HasTraits, Int, Property, Range, Tuple
+from traits.api import Bool, HasTraits, Int, Property, Range, Tuple
 
-from pyface.fields.i_field import IField
+from pyface.fields.i_editable_field import IEditableField
 
 
-class ISpinField(IField):
+class ISpinField(IEditableField):
     """ The spin field interface.
 
     This is for spinners holding integer values.
@@ -34,6 +34,9 @@ class ISpinField(IField):
     #: The maximum value
     maximum = Property(Int, observe="bounds")
 
+    #: Whether the values wrap around at maximum and minimum.
+    wrap = Bool()
+
 
 class MSpinField(HasTraits):
 
@@ -49,6 +52,9 @@ class MSpinField(HasTraits):
     #: The maximum value for the spinner
     maximum = Property(Int, observe="bounds")
 
+    #: Whether the values wrap around at maximum and minimum.
+    wrap = Bool()
+
     # ------------------------------------------------------------------------
     # object interface
     # ------------------------------------------------------------------------
@@ -69,21 +75,24 @@ def _initialize_control(self):
         super()._initialize_control()
         self._set_control_bounds(self.bounds)
         self._set_control_value(self.value)
+        self._set_control_wrap(self.wrap)
 
     def _add_event_listeners(self):
         """ Set up toolkit-specific bindings for events """
         super()._add_event_listeners()
         self.observe(self._bounds_updated, "bounds", dispatch="ui")
+        self.observe(self._wrap_updated, "wrap", dispatch="ui")
         if self.control is not None:
             self._observe_control_value()
 
     def _remove_event_listeners(self):
         """ Remove toolkit-specific bindings for events """
-        if self.control is not None:
-            self._observe_control_value(remove=True)
         self.observe(
             self._bounds_updated, "bounds", dispatch="ui", remove=True
         )
+        self.observe(
+            self._wrap_updated, "wrap", dispatch="ui", remove=True
+        )
         super()._remove_event_listeners()
 
     # Toolkit control interface ---------------------------------------------
@@ -96,6 +105,14 @@ def _set_control_bounds(self, bounds):
         """ Toolkit specific method to set the control's bounds. """
         raise NotImplementedError()
 
+    def _get_control_wrap(self):
+        """ Toolkit specific method to get whether the control wraps. """
+        raise NotImplementedError
+
+    def _set_control_wrap(self, wrap):
+        """ Toolkit specific method to set whether the control wraps. """
+        raise NotImplementedError
+
     # Trait property handlers -----------------------------------------------
 
     def _get_minimum(self):
@@ -130,3 +147,7 @@ def _value_default(self):
     def _bounds_updated(self, event):
         if self.control is not None:
             self._set_control_bounds(self.bounds)
+
+    def _wrap_updated(self, event):
+        if self.control is not None:
+            self._set_control_wrap(event.new)
diff --git a/pyface/fields/i_text_field.py b/pyface/fields/i_text_field.py
index eff0066bc..0e6427642 100644
--- a/pyface/fields/i_text_field.py
+++ b/pyface/fields/i_text_field.py
@@ -13,10 +13,10 @@
 
 from traits.api import Bool, Enum, HasTraits, Str
 
-from pyface.fields.i_field import IField
+from pyface.fields.i_editable_field import IEditableField
 
 
-class ITextField(IField):
+class ITextField(IEditableField):
     """ The text field interface. """
 
     #: The value held by the field.
@@ -58,13 +58,11 @@ class MTextField(HasTraits):
     # ------------------------------------------------------------------------
 
     def _initialize_control(self):
+        super()._initialize_control()
         self._set_control_echo(self.echo)
-        self._set_control_value(self.value)
         self._set_control_placeholder(self.placeholder)
         self._set_control_read_only(self.read_only)
 
-        super()._initialize_control()
-
     def _add_event_listeners(self):
         """ Set up toolkit-specific bindings for events """
         super()._add_event_listeners()
@@ -74,17 +72,15 @@ def _add_event_listeners(self):
         self.observe(self._read_only_updated, "read_only", dispatch="ui")
         if self.control is not None:
             if self.update_text == "editing_finished":
+                self._observe_control_value(remove=True)
                 self._observe_control_editing_finished()
-            else:
-                self._observe_control_value()
 
     def _remove_event_listeners(self):
         """ Remove toolkit-specific bindings for events """
         if self.control is not None:
             if self.update_text == "editing_finished":
                 self._observe_control_editing_finished(remove=True)
-            else:
-                self._observe_control_value(remove=True)
+                self._observe_control_value()
         self.observe(
             self._update_text_updated,
             "update_text",
diff --git a/pyface/fields/i_time_field.py b/pyface/fields/i_time_field.py
index 18cf40a24..3d63d79b7 100644
--- a/pyface/fields/i_time_field.py
+++ b/pyface/fields/i_time_field.py
@@ -14,10 +14,10 @@
 
 from traits.api import HasTraits, Time
 
-from pyface.fields.i_field import IField
+from pyface.fields.i_editable_field import IEditableField
 
 
-class ITimeField(IField):
+class ITimeField(IEditableField):
     """ The time field interface.
 
     This is for a field that edits a datetime.time value.
@@ -37,22 +37,6 @@ class MTimeField(HasTraits):
     # Private interface
     # ------------------------------------------------------------------------
 
-    def _initialize_control(self):
-        super(MTimeField, self)._initialize_control()
-        self._set_control_value(self.value)
-
-    def _add_event_listeners(self):
-        """ Set up toolkit-specific bindings for events """
-        super(MTimeField, self)._add_event_listeners()
-        if self.control is not None:
-            self._observe_control_value()
-
-    def _remove_event_listeners(self):
-        """ Remove toolkit-specific bindings for events """
-        if self.control is not None:
-            self._observe_control_value(remove=True)
-        super(MTimeField, self)._remove_event_listeners()
-
     # Trait defaults --------------------------------------------------------
 
     def _value_default(self):
diff --git a/pyface/fields/i_toggle_field.py b/pyface/fields/i_toggle_field.py
index 017b4f7bd..be68a1228 100644
--- a/pyface/fields/i_toggle_field.py
+++ b/pyface/fields/i_toggle_field.py
@@ -13,11 +13,11 @@
 
 from traits.api import Bool, HasTraits, Str
 
-from pyface.fields.i_field import IField
+from pyface.fields.i_editable_field import IEditableField
 from pyface.ui_traits import Image
 
 
-class IToggleField(IField):
+class IToggleField(IEditableField):
     """ The toggle field interface.
 
     This is for a toggle between two states, represented by a boolean value.
@@ -62,13 +62,9 @@ def _add_event_listeners(self):
         super()._add_event_listeners()
         self.observe(self._text_updated, "text", dispatch="ui")
         self.observe(self._icon_updated, "icon", dispatch="ui")
-        if self.control is not None:
-            self._observe_control_value()
 
     def _remove_event_listeners(self):
         """ Remove toolkit-specific bindings for events """
-        if self.control is not None:
-            self._observe_control_value(remove=True)
         self.observe(self._text_updated, "text", dispatch="ui", remove=True)
         self.observe(self._icon_updated, "icon", dispatch="ui", remove=True)
         super()._remove_event_listeners()
diff --git a/pyface/fields/image_field.py b/pyface/fields/image_field.py
new file mode 100644
index 000000000..3f756a098
--- /dev/null
+++ b/pyface/fields/image_field.py
@@ -0,0 +1,16 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The image field widget. """
+
+# Import the toolkit specific version.
+from pyface.toolkit import toolkit_object
+
+ImageField = toolkit_object("fields.image_field:ImageField")
diff --git a/pyface/fields/label_field.py b/pyface/fields/label_field.py
new file mode 100644
index 000000000..d1d4dba11
--- /dev/null
+++ b/pyface/fields/label_field.py
@@ -0,0 +1,16 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The label field widget. """
+
+# Import the toolkit specific version.
+from pyface.toolkit import toolkit_object
+
+LabelField = toolkit_object("fields.label_field:LabelField")
diff --git a/pyface/fields/tests/field_mixin.py b/pyface/fields/tests/field_mixin.py
index 132cfcc0c..80d4421bd 100644
--- a/pyface/fields/tests/field_mixin.py
+++ b/pyface/fields/tests/field_mixin.py
@@ -14,4 +14,11 @@
 
 class FieldMixin(LayoutWidgetMixin):
     """ Mixin which provides standard methods for all fields. """
-    pass
+
+    def test_text_field_alignment(self):
+        self._create_widget_control()
+
+        self.widget.alignment = 'right'
+        self.gui.process_events()
+
+        self.assertEqual(self.widget._get_control_alignment(), 'right')
diff --git a/pyface/fields/tests/test_api.py b/pyface/fields/tests/test_api.py
new file mode 100644
index 000000000..0b37df01e
--- /dev/null
+++ b/pyface/fields/tests/test_api.py
@@ -0,0 +1,35 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" Test for pyface.api """
+
+import unittest
+
+
+class TestApi(unittest.TestCase):
+    """ Test importable items in any environment."""
+
+    def test_api_importable(self):
+        # make sure api is importable with the most minimal
+        # required dependencies, including in the absence of toolkit backends.
+        from pyface.fields import api   # noqa: F401
+
+    def test_public_attrs(self):
+        # make sure everything advertised by dir() is available except optional
+        from pyface.fields import api
+
+        attrs = [
+            name
+            for name in dir(api)
+            if not name.startswith('_')
+        ]
+        for attr in attrs:
+            with self.subTest(attr=attr):
+                self.assertIsNotNone(getattr(api, attr, None))
diff --git a/pyface/fields/tests/test_image_field.py b/pyface/fields/tests/test_image_field.py
new file mode 100644
index 000000000..7b32c6919
--- /dev/null
+++ b/pyface/fields/tests/test_image_field.py
@@ -0,0 +1,39 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+
+import unittest
+
+from traits.testing.optional_dependencies import numpy as np, requires_numpy
+
+from ..image_field import ImageField
+from .field_mixin import FieldMixin
+
+
+@requires_numpy
+class ImageFieldMixin(FieldMixin, unittest.TestCase):
+
+    def setUp(self):
+        super().setUp()
+        self.data = np.full((32, 64, 4), 0xee, dtype='uint8')
+
+    def _create_widget_simple(self, **traits):
+        traits.setdefault("tooltip", "Dummy")
+        return ImageField(**traits)
+
+    # Tests ------------------------------------------------------------------
+
+    def test_image_field(self):
+        self._create_widget_control()
+
+        self.widget.value = 'splash'
+        self.gui.process_events()
+
+        self.assertIsNotNone(self.widget._get_control_value())
diff --git a/pyface/fields/tests/test_label_field.py b/pyface/fields/tests/test_label_field.py
new file mode 100644
index 000000000..219c0d1ab
--- /dev/null
+++ b/pyface/fields/tests/test_label_field.py
@@ -0,0 +1,43 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+
+import unittest
+
+
+from pyface.image_resource import ImageResource
+from ..label_field import LabelField
+from .field_mixin import FieldMixin
+
+
+class TestLabelField(FieldMixin, unittest.TestCase):
+
+    def _create_widget_simple(self, **traits):
+        traits.setdefault("value", "Label")
+        traits.setdefault("tooltip", "Dummy")
+        return LabelField(**traits)
+
+    # Tests ------------------------------------------------------------------
+
+    def test_label_field(self):
+        self._create_widget_control()
+
+        self.widget.value = "Test"
+        self.gui.process_events()
+
+        self.assertEqual(self.widget._get_control_value(), "Test")
+
+    def test_label_field_image(self):
+        self._create_widget_control()
+        image = ImageResource("question")
+
+        # XXX can't validate icon values currently, so just a smoke test
+        self.widget.image = image
+        self.gui.process_events()
diff --git a/pyface/fields/tests/test_spin_field.py b/pyface/fields/tests/test_spin_field.py
index ec7cda343..2ada52e93 100644
--- a/pyface/fields/tests/test_spin_field.py
+++ b/pyface/fields/tests/test_spin_field.py
@@ -51,3 +51,11 @@ def test_spin_field_bounds(self):
         self.assertEqual(self.widget._get_control_bounds(), (10, 50))
         self.assertEqual(self.widget._get_control_value(), 10)
         self.assertEqual(self.widget.value, 10)
+
+    def test_spin_field_wrap(self):
+        self._create_widget_control()
+
+        self.widget.wrap = True
+        self.gui.process_events()
+
+        self.assertTrue(self.widget._get_control_wrap())
diff --git a/pyface/fields/tests/test_text_field.py b/pyface/fields/tests/test_text_field.py
index 53230b4e4..f995e01e4 100644
--- a/pyface/fields/tests/test_text_field.py
+++ b/pyface/fields/tests/test_text_field.py
@@ -52,7 +52,7 @@ def test_text_field_echo(self):
         self.assertEqual(self.widget._get_control_echo(), "password")
 
     @unittest.skipIf(
-        is_wx, "Can't change password mode for wx after control " "creation."
+        is_wx, "Can't change password mode for wx after control creation."
     )
     def test_text_field_echo_change(self):
         self._create_widget_control()
@@ -71,17 +71,6 @@ def test_text_field_placeholder(self):
         self.assertEqual(self.widget._get_control_placeholder(), "test")
 
     def test_text_field_readonly(self):
-        self.widget.read_only = True
-        self._create_widget_control()
-
-        self.gui.process_events()
-
-        self.assertEqual(self.widget._get_control_read_only(), True)
-
-    @unittest.skipIf(
-        is_wx, "Can't change read_only mode for wx after control " "creation."
-    )
-    def test_text_field_readonly_change(self):
         self._create_widget_control()
 
         self.widget.read_only = True
diff --git a/pyface/font.py b/pyface/font.py
index 5d4434930..7d287f00e 100644
--- a/pyface/font.py
+++ b/pyface/font.py
@@ -247,6 +247,11 @@ def __init__(self, default_value=NoDefaultSpecified, **metadata):
         super().__init__(default_value, **metadata)
 
     def validate(self, object, name, value):
+        """Validate the trait
+
+        This is a CFloat trait that also accepts percentage strings.  Values
+        must be in the range 50 to 200 inclusive
+        """
         if isinstance(value, str) and value.endswith('%'):
             value = value[:-1]
         value = STRETCHES.get(value, value)
@@ -256,6 +261,7 @@ def validate(self, object, name, value):
         return value
 
     def info(self):
+        """Describe the trait"""
         info = (
             "a float from 50 to 200, "
             "a value that can convert to a float from 50 to 200, "
@@ -284,6 +290,11 @@ def __init__(self, default_value=NoDefaultSpecified, **metadata):
         super().__init__(default_value, **metadata)
 
     def validate(self, object, name, value):
+        """Validate the trait
+
+        This is a CFloat trait that also accepts strings with 'pt' or 'px'
+        suffixes.  Values must be positive.
+        """
         if (
             isinstance(value, str)
             and (value.endswith('pt') or value.endswith('px'))
@@ -296,6 +307,7 @@ def validate(self, object, name, value):
         return value
 
     def info(self):
+        """Describe the trait"""
         info = (
             "a positive float, a value that can convert to a positive float, "
         )
@@ -343,7 +355,7 @@ def from_toolkit(cls, toolkit_font):
 
         Parameters
         ----------
-        toolkit_font : any
+        toolkit_font : Any
             A toolkit font to be converted to a corresponding class instance,
             within the limitations of the options supported by the class.
         """
@@ -358,7 +370,7 @@ def to_toolkit(self):
 
         Returns
         -------
-        toolkit_font : any
+        toolkit_font : Any
             A toolkit font which matches the property of the font as
             closely as possible given the constraints of the toolkit.
         """
diff --git a/pyface/gui_application.py b/pyface/gui_application.py
index 1f285c948..ee4e9a46c 100644
--- a/pyface/gui_application.py
+++ b/pyface/gui_application.py
@@ -116,7 +116,7 @@ def create_window(self, **kwargs):
 
         Returns
         -------
-        window : IWindow instance or None
+        window : IWindow  or None
             The new IWindow instance.
         """
         window = self.window_factory(application=self, **kwargs)
diff --git a/pyface/i_application_window.py b/pyface/i_application_window.py
index 2a5470d7d..5f32ddae1 100644
--- a/pyface/i_application_window.py
+++ b/pyface/i_application_window.py
@@ -13,8 +13,9 @@
 
 from traits.api import HasTraits, Instance, List
 
-
-from pyface.action.api import MenuBarManager, StatusBarManager, ToolBarManager
+from pyface.action.i_menu_bar_manager import IMenuBarManager
+from pyface.action.i_status_bar_manager import IStatusBarManager
+from pyface.action.i_tool_bar_manager import IToolBarManager
 from pyface.i_window import IWindow
 from pyface.ui_traits import Image
 
@@ -25,10 +26,10 @@ class IApplicationWindow(IWindow):
     The application window has support for a menu bar, tool bar and a status
     bar (all of which are optional).
 
-    Usage
+    Notes
     -----
 
-    Create a sub-class of this class and override the
+    To use, create a sub-class of this class and override the
     :py:meth:`._create_contents` method.
     """
 
@@ -37,18 +38,14 @@ class IApplicationWindow(IWindow):
     #: The window icon.  The default is toolkit specific.
     icon = Image()
 
-    #: The menu bar manager (None iff there is no menu bar).
-    menu_bar_manager = Instance(MenuBarManager)
-
-    #: The status bar manager (None iff there is no status bar).
-    status_bar_manager = Instance(StatusBarManager)
+    #: The menu bar manager for the window.
+    menu_bar_manager = Instance(IMenuBarManager)
 
-    #: The tool bar manager (None iff there is no tool bar).
-    tool_bar_manager = Instance(ToolBarManager)
+    #: The status bar manager for the window.
+    status_bar_manager = Instance(IStatusBarManager)
 
-    #: If the underlying toolkit supports multiple toolbars, you can use this
-    #: list instead of the single ToolBarManager instance above.
-    tool_bar_managers = List(ToolBarManager)
+    #: The collection of tool bar managers for the window.
+    tool_bar_managers = List(Instance(IToolBarManager))
 
     # ------------------------------------------------------------------------
     # Protected 'IApplicationWindow' interface.
@@ -116,6 +113,18 @@ class MApplicationWindow(HasTraits):
     Implements: destroy(), _create_trim_widgets()
     """
 
+    #: The icon to display in the application window title bar.
+    icon = Image()
+
+    #: The menu bar manager for the window.
+    menu_bar_manager = Instance(IMenuBarManager)
+
+    #: The status bar manager for the window.
+    status_bar_manager = Instance(IStatusBarManager)
+
+    #: The collection of tool bar managers for the window.
+    tool_bar_managers = List(Instance(IToolBarManager))
+
     # ------------------------------------------------------------------------
     # 'IWidget' interface.
     # ------------------------------------------------------------------------
@@ -126,9 +135,6 @@ def destroy(self):
         if self.menu_bar_manager is not None:
             self.menu_bar_manager.destroy()
 
-        if self.tool_bar_manager is not None:
-            self.tool_bar_manager.destroy()
-
         if self.status_bar_manager is not None:
             self.status_bar_manager.destroy()
 
diff --git a/pyface/i_gui.py b/pyface/i_gui.py
index b950b617f..9b5fa6771 100644
--- a/pyface/i_gui.py
+++ b/pyface/i_gui.py
@@ -49,7 +49,7 @@ def __init__(self, splash_screen=None):
 
         Parameters
         ----------
-        splash_screen : ISplashScreen instance or None
+        splash_screen : ISplashScreen or None
             An optional splash screen that will be displayed until the event
             loop is started.
         """
@@ -78,7 +78,7 @@ def invoke_after(cls, millisecs, callable, *args, **kw):
         ----------
         millisecs : float
             Delay in milliseconds
-        callable : callable
+        callable : Callable
             Callable to be called after the delay
         args, kwargs :
             Arguments and keyword arguments to be used when calling.
@@ -90,7 +90,7 @@ def invoke_later(cls, callable, *args, **kw):
 
         Parameters
         ----------
-        callable : callable
+        callable : Callable
             Callable to be called after the delay
         args, kwargs :
             Arguments and keyword arguments to be used when calling.
@@ -104,11 +104,11 @@ def set_trait_after(cls, millisecs, obj, trait_name, new):
         ----------
         millisecs : float
             Delay in milliseconds
-        obj : HasTraits instance
+        obj : traits.has_traits.HasTraits
             Object on which the trait is to be set
         trait_name : str
             The name of the trait to set
-        new : any
+        new : Any
             The value to set.
         """
 
@@ -118,11 +118,11 @@ def set_trait_later(cls, obj, trait_name, new):
 
         Parameters
         ----------
-        obj : HasTraits instance
+        obj : traits.has_traits.HasTraits
             Object on which the trait is to be set
         trait_name : str
             The name of the trait to set
-        new : any
+        new : Any
             The value to set.
         """
 
diff --git a/pyface/i_image_resource.py b/pyface/i_image_resource.py
index c69315284..b1874198b 100644
--- a/pyface/i_image_resource.py
+++ b/pyface/i_image_resource.py
@@ -14,7 +14,6 @@
 from traits.api import HasTraits, List, Str
 
 from pyface.i_image import IImage
-from pyface.resource_manager import resource_manager
 from pyface.resource.resource_path import resource_module, resource_path
 
 
@@ -125,11 +124,13 @@ def _get_ref(self, size=None):
 
         Returns
         -------
-        ref : ImageReference instance
+        ref : ImageReference
             The reference to the requested image.
         """
 
         if self._ref is None:
+            from pyface.resource_manager import resource_manager
+
             self._ref = resource_manager.locate_image(
                 self.name, self.search_path, size
             )
@@ -161,7 +162,7 @@ def _get_image_not_found(cls):
 
         Returns
         -------
-        not_found : ImageResource instance
+        not_found : ImageResource
             An image resource for the the 'not found' image.
         """
 
diff --git a/pyface/i_python_shell.py b/pyface/i_python_shell.py
index e98582f9c..039f72f64 100644
--- a/pyface/i_python_shell.py
+++ b/pyface/i_python_shell.py
@@ -38,7 +38,7 @@ def interpreter(self):
 
         Returns
         -------
-        interpreter : InteractiveInterpreter instance
+        interpreter : InteractiveInterpreter
             Returns the InteractiveInterpreter instance.
         """
 
@@ -49,7 +49,7 @@ def bind(self, name, value):
         ----------
         name : str
             The python idetifier to bind the value to.
-        value : any
+        value : Any
             The python object to be bound into the interpreter's namespace.
         """
 
@@ -118,7 +118,7 @@ def bind(self, name, value):
         ----------
         name : str
             The python idetifier to bind the value to.
-        value : any
+        value : Any
             The python object to be bound into the interpreter's namespace.
         """
         self.interpreter().locals[name] = value
diff --git a/pyface/i_system_metrics.py b/pyface/i_system_metrics.py
index c86c28245..42382cbdc 100644
--- a/pyface/i_system_metrics.py
+++ b/pyface/i_system_metrics.py
@@ -11,7 +11,7 @@
 """ The interface to system metrics (screen width and height etc). """
 
 
-from traits.api import HasTraits, Int, Interface, Tuple
+from traits.api import HasTraits, Int, Interface, List, Tuple
 
 
 class ISystemMetrics(Interface):
@@ -19,12 +19,15 @@ class ISystemMetrics(Interface):
 
     # 'ISystemMetrics' interface -------------------------------------------
 
-    #: The width of the screen in pixels.
+    #: The width of the main screen in pixels.
     screen_width = Int()
 
-    #: The height of the screen in pixels.
+    #: The height of the main screen in pixels.
     screen_height = Int()
 
+    #: The height and width of each screen in pixels
+    screen_sizes = List(Tuple(Int, Int))
+
     #: Background color of a standard dialog window as a tuple of RGB values
     #: between 0.0 and 1.0.
     # FIXME v3: Why isn't this a traits colour?
diff --git a/pyface/i_widget.py b/pyface/i_widget.py
index 0cd6ad7ad..dd71465cd 100644
--- a/pyface/i_widget.py
+++ b/pyface/i_widget.py
@@ -77,7 +77,7 @@ def create(self, parent=None):
         """ Creates the toolkit specific control.
 
         This method should create the control and assign it to the
-        :py:attr:``control`` trait.
+        :py:attr:`control` trait.
         """
 
     def destroy(self):
diff --git a/pyface/qt/QtCore.py b/pyface/qt/QtCore.py
index 1636ef1cc..801fcba10 100644
--- a/pyface/qt/QtCore.py
+++ b/pyface/qt/QtCore.py
@@ -9,19 +9,7 @@
 # Thanks for using Enthought open source!
 from . import qt_api
 
-if qt_api == "pyqt":
-    from PyQt4.QtCore import *
-
-    from PyQt4.QtCore import pyqtProperty as Property
-    from PyQt4.QtCore import pyqtSignal as Signal
-    from PyQt4.QtCore import pyqtSlot as Slot
-    from PyQt4.Qt import QCoreApplication
-    from PyQt4.Qt import Qt
-
-    __version__ = QT_VERSION_STR
-    __version_info__ = tuple(map(int, QT_VERSION_STR.split(".")))
-
-elif qt_api == "pyqt5":
+if qt_api == "pyqt5":
     from PyQt5.QtCore import *
 
     from PyQt5.QtCore import pyqtProperty as Property
diff --git a/pyface/qt/QtGui.py b/pyface/qt/QtGui.py
index 25d6c82c8..632cb247d 100644
--- a/pyface/qt/QtGui.py
+++ b/pyface/qt/QtGui.py
@@ -9,17 +9,7 @@
 # Thanks for using Enthought open source!
 from . import qt_api
 
-if qt_api == "pyqt":
-    from PyQt4.Qt import QKeySequence, QTextCursor
-    from PyQt4.QtGui import *
-
-    # forward-compatible font weights
-    # see https://doc.qt.io/qt-5/qfont.html#Weight-enum
-    QFont.Weight.ExtraLight = 12
-    QFont.Weight.Medium = 57
-    QFont.Weight.ExtraBold = 81
-
-elif qt_api == "pyqt5":
+if qt_api == "pyqt5":
     from PyQt5.QtGui import *
     from PyQt5.QtWidgets import *
     from PyQt5.QtPrintSupport import *
diff --git a/pyface/qt/QtNetwork.py b/pyface/qt/QtNetwork.py
index e392f878f..0b3b2658d 100644
--- a/pyface/qt/QtNetwork.py
+++ b/pyface/qt/QtNetwork.py
@@ -9,10 +9,7 @@
 # Thanks for using Enthought open source!
 from . import qt_api
 
-if qt_api == "pyqt":
-    from PyQt4.QtNetwork import *
-
-elif qt_api == "pyqt5":
+if qt_api == "pyqt5":
     from PyQt5.QtNetwork import *
 
 elif qt_api == "pyqt6":
diff --git a/pyface/qt/QtOpenGL.py b/pyface/qt/QtOpenGL.py
index a7794f654..9d9b6437f 100644
--- a/pyface/qt/QtOpenGL.py
+++ b/pyface/qt/QtOpenGL.py
@@ -9,10 +9,7 @@
 # Thanks for using Enthought open source!
 from . import qt_api
 
-if qt_api == "pyqt":
-    from PyQt4.QtOpenGL import *
-
-elif qt_api == "pyqt5":
+if qt_api == "pyqt5":
     from PyQt5.QtOpenGL import *
     from PyQt5.QtWidgets import QOpenGLWidget
 
diff --git a/pyface/qt/QtOpenGLWidgets.py b/pyface/qt/QtOpenGLWidgets.py
new file mode 100644
index 000000000..87314a5a2
--- /dev/null
+++ b/pyface/qt/QtOpenGLWidgets.py
@@ -0,0 +1,24 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+from . import qt_api
+
+if qt_api == "pyqt5":
+    from PyQt5.QtOpenGL import *
+    from PyQt5.QtWidgets import QOpenGLWidget
+
+elif qt_api == "pyqt6":
+    from PyQt6.QtOpenGLWidgets import *
+
+elif qt_api == "pyside6":
+    from PySide6.QtOpenGLWidgets import *
+
+else:
+    from PySide2.QtOpenGL import *
+    from PySide2.QtWidgets import QOpenGLWidget
diff --git a/pyface/qt/QtScript.py b/pyface/qt/QtScript.py
index 0a9079f06..841087ecc 100644
--- a/pyface/qt/QtScript.py
+++ b/pyface/qt/QtScript.py
@@ -7,12 +7,8 @@
 # is also available online at http://www.enthought.com/licenses/BSD.txt
 #
 # Thanks for using Enthought open source!
-from . import qt_api
 
-if qt_api == "pyqt":
-    from PyQt4.QtScript import *
 
-else:
-    import warnings
+import warnings
 
-    warnings.warn(DeprecationWarning("QtScript is not supported in PyQt5/PySide2"))
+warnings.warn(DeprecationWarning("QtScript is not supported after Qt4"))
diff --git a/pyface/qt/QtSvg.py b/pyface/qt/QtSvg.py
index 4c13c77aa..5a3160370 100644
--- a/pyface/qt/QtSvg.py
+++ b/pyface/qt/QtSvg.py
@@ -9,17 +9,18 @@
 # Thanks for using Enthought open source!
 from . import qt_api
 
-if qt_api == "pyqt":
-    from PyQt4.QtSvg import *
-
-elif qt_api == "pyqt5":
+if qt_api == "pyqt5":
     from PyQt5.QtSvg import *
 
 elif qt_api == "pyqt6":
     from PyQt6.QtSvg import *
+    # Backwards compatibility imports
+    from PyQt6.QtSvgWidgets import *
 
 elif qt_api == "pyside6":
     from PySide6.QtSvg import *
+    # Backwards compatibility imports
+    from PySide6.QtSvgWidgets import *
 
 else:
     from PySide2.QtSvg import *
diff --git a/pyface/qt/QtSvgWidgets.py b/pyface/qt/QtSvgWidgets.py
new file mode 100644
index 000000000..8ed4d4565
--- /dev/null
+++ b/pyface/qt/QtSvgWidgets.py
@@ -0,0 +1,24 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+from . import qt_api
+
+if qt_api == "pyqt5":
+    # Forwards compatibility imports
+    from PyQt5.QtSvg import *
+
+elif qt_api == "pyqt6":
+    from PyQt6.QtSvgWidgets import *
+
+elif qt_api == "pyside6":
+    from PySide6.QtSvgWidgets import *
+
+else:
+    # Forwards compatibility imports
+    from PySide2.QtSvg import *
diff --git a/pyface/qt/QtTest.py b/pyface/qt/QtTest.py
index db3fe2410..e1544b838 100644
--- a/pyface/qt/QtTest.py
+++ b/pyface/qt/QtTest.py
@@ -9,10 +9,7 @@
 # Thanks for using Enthought open source!
 from . import qt_api
 
-if qt_api == "pyqt":
-    from PyQt4.QtTest import *
-
-elif qt_api == "pyqt5":
+if qt_api == "pyqt5":
     from PyQt5.QtTest import *
 
 elif qt_api == "pyqt6":
diff --git a/pyface/qt/QtWebKit.py b/pyface/qt/QtWebKit.py
index c2b186eb9..8ca944811 100644
--- a/pyface/qt/QtWebKit.py
+++ b/pyface/qt/QtWebKit.py
@@ -9,10 +9,7 @@
 # Thanks for using Enthought open source!
 from . import qt_api
 
-if qt_api == "pyqt":
-    from PyQt4.QtWebKit import *
-
-elif qt_api == "pyqt5":
+if qt_api == "pyqt5":
     from PyQt5.QtWidgets import *
 
     try:
diff --git a/pyface/qt/QtWidgets.py b/pyface/qt/QtWidgets.py
new file mode 100644
index 000000000..73656afdf
--- /dev/null
+++ b/pyface/qt/QtWidgets.py
@@ -0,0 +1,22 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+from . import qt_api
+
+if qt_api == "pyqt5":
+    from PyQt5.QtWidgets import *
+
+elif qt_api == "pyqt6":
+    from PyQt6.QtWidgets import *
+
+elif qt_api == "pyside6":
+    from PySide6.QtWidgets import *
+
+else:
+    from PySide2.QtWidgets import *
diff --git a/pyface/qt/__init__.py b/pyface/qt/__init__.py
index 8cec68f29..69e7fd673 100644
--- a/pyface/qt/__init__.py
+++ b/pyface/qt/__init__.py
@@ -18,7 +18,6 @@
     ("pyside6", "PySide6"),
     ("pyqt5", "PyQt5"),
     ("pyqt6", "PyQt6"),
-    ("pyqt", "PyQt4"),
 ]
 api_names, modules = zip(*QtAPIs)
 
@@ -60,7 +59,7 @@
     raise RuntimeError(msg)
 
 # useful constants
-is_qt4 = qt_api in {"pyqt"}
+is_qt4 = False
 is_qt5 = qt_api in {"pyqt5", "pyside2"}
 is_qt6 = qt_api in {"pyqt6", "pyside6"}
 is_pyqt = qt_api in {"pyqt", "pyqt5", "pyqt6"}
diff --git a/pyface/single_choice_dialog.py b/pyface/single_choice_dialog.py
index c7f8d278c..e187e6475 100644
--- a/pyface/single_choice_dialog.py
+++ b/pyface/single_choice_dialog.py
@@ -38,7 +38,7 @@ def choose_one(parent, message, choices, title="Choose", cancel=True):
 
     Returns
     -------
-    choice : any
+    choice : Any
         The selected object, or None if cancelled.
     """
     dialog = SingleChoiceDialog(
diff --git a/pyface/splash_screen_log_handler.py b/pyface/splash_screen_log_handler.py
index 4ccf4dc78..50ec28c0f 100644
--- a/pyface/splash_screen_log_handler.py
+++ b/pyface/splash_screen_log_handler.py
@@ -22,7 +22,7 @@ def __init__(self, splash_screen):
 
         Parameters
         ----------
-        splash_screen : ISplashScreen instance
+        splash_screen : ISplashScreen
             The splash screen being used to display the log messages
         """
         # Base class constructor.
@@ -36,7 +36,7 @@ def emit(self, record):
 
         Parameters
         ----------
-        record : logging record instance
+        record : logging record
             The log record to be displayed.
         """
         self._splash_screen.text = str(record.getMessage()) + "..."
diff --git a/pyface/tasks/action/api.py b/pyface/tasks/action/api.py
index 5e4a33d97..151e59932 100644
--- a/pyface/tasks/action/api.py
+++ b/pyface/tasks/action/api.py
@@ -78,7 +78,8 @@
     SMenuBar,
     SToolBar,
 )
-from .schema_addition import SchemaAddition
+# deprecated: will be removed in a future Pyface release
+from pyface.action.schema.schema_addition import SchemaAddition
 from .task_action import (
     CentralPaneAction,
     DockPaneAction,
diff --git a/pyface/tasks/action/dock_pane_toggle_group.py b/pyface/tasks/action/dock_pane_toggle_group.py
index 603cdfc59..701c2f8f8 100644
--- a/pyface/tasks/action/dock_pane_toggle_group.py
+++ b/pyface/tasks/action/dock_pane_toggle_group.py
@@ -10,7 +10,6 @@
 """ A Group for toggling the visibility of a task's dock panes. """
 
 
-from pyface.action.api import Action, ActionItem, Group
 from traits.api import (
     cached_property,
     Instance,
@@ -21,6 +20,7 @@
 )
 
 
+from pyface.action.api import Action, Group
 from pyface.tasks.i_dock_pane import IDockPane
 
 
@@ -123,6 +123,7 @@ def get_manager(self):
     def _dock_panes_updated(self, event):
         """Recreate the group items when dock panes have been added/removed.
         """
+        from pyface.action.action_item import ActionItem
 
         # Remove the previous group items.
         self.destroy()
diff --git a/pyface/tasks/action/task_action.py b/pyface/tasks/action/task_action.py
index 986e1722a..401eb28bc 100644
--- a/pyface/tasks/action/task_action.py
+++ b/pyface/tasks/action/task_action.py
@@ -12,7 +12,9 @@
 from traits.api import Instance, Property, Str, cached_property
 
 
-from pyface.tasks.api import Editor, Task, TaskPane
+from pyface.tasks.i_editor import IEditor
+from pyface.tasks.task import Task
+from pyface.tasks.i_task_pane import ITaskPane
 from pyface.action.listening_action import ListeningAction
 
 
@@ -74,7 +76,7 @@ class CentralPaneAction(TaskAction):
     # CentralPaneAction interface -----------------------------------------#
 
     #: The central pane with which the action is associated.
-    central_pane = Property(Instance(TaskPane), observe="task")
+    central_pane = Property(Instance(ITaskPane), observe="task")
 
     # ------------------------------------------------------------------------
     # Protected interface.
@@ -101,7 +103,7 @@ class DockPaneAction(TaskAction):
     # DockPaneAction interface ---------------------------------------------
 
     #: The dock pane with which the action is associated. Set by the framework.
-    dock_pane = Property(Instance(TaskPane), observe="task")
+    dock_pane = Property(Instance(ITaskPane), observe="task")
 
     #: The ID of the dock pane with which the action is associated.
     dock_pane_id = Str()
@@ -132,7 +134,7 @@ class EditorAction(CentralPaneAction):
 
     #: The active editor in the central pane with which the action is associated.
     active_editor = Property(
-        Instance(Editor), observe="central_pane.active_editor"
+        Instance(IEditor), observe="central_pane.active_editor"
     )
 
     # ------------------------------------------------------------------------
diff --git a/pyface/tasks/action/task_toggle_group.py b/pyface/tasks/action/task_toggle_group.py
index 97c4d8001..362b959c6 100644
--- a/pyface/tasks/action/task_toggle_group.py
+++ b/pyface/tasks/action/task_toggle_group.py
@@ -9,12 +9,11 @@
 # Thanks for using Enthought open source!
 
 
-from pyface.action.api import Action, ActionItem, Group
+from pyface.action.api import Action, Group
 from traits.api import Any, List, Instance, Property, Str, observe
 
 
 from pyface.tasks.task import Task
-from pyface.tasks.task_window import TaskWindow
 
 
 class TaskToggleAction(Action):
@@ -89,13 +88,15 @@ class TaskToggleGroup(Group):
     manager = Any()
 
     #: The window that contains the group.
-    window = Instance(TaskWindow)
+    window = Instance("pyface.tasks.task_window.TaskWindow")
 
     # ------------------------------------------------------------------------
     # Private interface.
     # ------------------------------------------------------------------------
 
     def _get_items(self):
+        from pyface.action.api import ActionItem
+
         items = []
         if len(self.window.tasks) > 1:
             # at least two tasks, so something to toggle
diff --git a/pyface/tasks/action/task_window_toggle_group.py b/pyface/tasks/action/task_window_toggle_group.py
index 210450bb9..9a6d70129 100644
--- a/pyface/tasks/action/task_window_toggle_group.py
+++ b/pyface/tasks/action/task_window_toggle_group.py
@@ -9,9 +9,10 @@
 # Thanks for using Enthought open source!
 
 
-from pyface.action.api import Action, ActionItem, Group
 from traits.api import Any, Instance, List, Property, Str, observe
 
+from pyface.action.api import Action, Group
+
 
 class TaskWindowToggleAction(Action):
     """ An action for activating an application window.
@@ -94,6 +95,8 @@ def destroy(self):
     # -------------------------------------------------------------------------
 
     def _get_items(self):
+        from pyface.action.action_item import ActionItem
+
         items = []
         for window in self.application.windows:
             active = window == self.application.active_window
diff --git a/pyface/tasks/api.py b/pyface/tasks/api.py
index bab3d2653..36059a2f5 100644
--- a/pyface/tasks/api.py
+++ b/pyface/tasks/api.py
@@ -57,14 +57,6 @@
 
 """
 
-from .advanced_editor_area_pane import AdvancedEditorAreaPane
-from .split_editor_area_pane import SplitEditorAreaPane
-from .dock_pane import DockPane
-from .editor import Editor
-from .editor_area_pane import EditorAreaPane
-from .enaml_dock_pane import EnamlDockPane
-from .enaml_editor import EnamlEditor
-from .enaml_task_pane import EnamlTaskPane
 from .i_dock_pane import IDockPane
 from .i_editor import IEditor
 from .i_editor_area_pane import IEditorAreaPane
@@ -79,9 +71,72 @@
     HSplitter,
     VSplitter,
 )
-from .task_pane import TaskPane
-from .task_window import TaskWindow
 from .task_window_layout import TaskWindowLayout
-from .traits_dock_pane import TraitsDockPane
-from .traits_editor import TraitsEditor
-from .traits_task_pane import TraitsTaskPane
+
+
+# ----------------------------------------------------------------------------
+# Deferred imports
+# ----------------------------------------------------------------------------
+
+# These imports have the side-effect of performing toolkit selection
+
+_toolkit_imports = {
+    'AdvancedEditorAreaPane': "advanced_editor_area_pane",
+    'DockPane': "dock_pane",
+    'EditorAreaPane': "editor_area_pane",
+    'Editor': "editor",
+    'SplitEditorAreaPane': "split_editor_area_pane",
+    'TaskPane': "task_pane",
+}
+
+# These are pyface.* imports that have selection as a side-effect
+# TODO: refactor to delay imports where possible
+_relative_imports = {
+    'EnamlDockPane': "enaml_dock_pane",
+    'EnamlEditor': "enaml_editor",
+    'EnamlTaskPane': "enaml_task_pane",
+    'TaskWindow': "task_window",
+    'TraitsDockPane': "traits_dock_pane",
+    'TraitsEditor': "traits_editor",
+    'TraitsTaskPane': "traits_task_pane",
+}
+
+
+def __getattr__(name):
+    """Lazily load attributes with side-effects
+
+    In particular, lazily load toolkit backend names.  For efficiency, lazily
+    loaded objects are injected into the module namespace
+    """
+    # sentinel object for no result
+    not_found = object()
+    result = not_found
+
+    if name in _relative_imports:
+        from importlib import import_module
+        source = _relative_imports[name]
+        module = import_module(f"pyface.tasks.{source}")
+        result = getattr(module, name)
+
+    elif name in _toolkit_imports:
+        from pyface.toolkit import toolkit_object
+        source = _toolkit_imports[name]
+        result = toolkit_object(f"tasks.{source}:{name}")
+
+    if result is not_found:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+    globals()[name] = result
+    return result
+
+
+# ----------------------------------------------------------------------------
+# Introspection support
+# ----------------------------------------------------------------------------
+
+# the list of available names we report for introspection purposes
+_extra_names = set(_toolkit_imports) | set(_relative_imports)
+
+
+def __dir__():
+    return sorted(set(globals()) | _extra_names)
diff --git a/pyface/tasks/task.py b/pyface/tasks/task.py
index b091d3be6..753ff21be 100644
--- a/pyface/tasks/task.py
+++ b/pyface/tasks/task.py
@@ -8,7 +8,6 @@
 #
 # Thanks for using Enthought open source!
 
-from pyface.action.api import StatusBarManager
 from traits.api import Callable, HasTraits, Instance, List, Str
 
 
@@ -49,7 +48,7 @@ class Task(HasTraits):
     menu_bar = Instance(MenuBarSchema)
 
     #: The (optional) status bar for the task.
-    status_bar = Instance(StatusBarManager)
+    status_bar = Instance("pyface.action.status_bar_manager.StatusBarManager")
 
     #: The list of tool bars for the tasks.
     tool_bars = List(ToolBarSchema)
diff --git a/pyface/tasks/task_window.py b/pyface/tasks/task_window.py
index 854c20b95..6d9fe3aa6 100644
--- a/pyface/tasks/task_window.py
+++ b/pyface/tasks/task_window.py
@@ -11,8 +11,6 @@
 import logging
 
 
-from pyface.action.api import MenuBarManager, StatusBarManager, ToolBarManager
-from pyface.api import ApplicationWindow
 from traits.api import (
     Bool,
     Callable,
@@ -26,13 +24,17 @@
 )
 
 
+from pyface.action.i_menu_bar_manager import IMenuBarManager
+from pyface.action.i_status_bar_manager import IStatusBarManager
+from pyface.action.i_tool_bar_manager import IToolBarManager
+from pyface.application_window import ApplicationWindow
 from pyface.tasks.action.task_action_manager_builder import (
     TaskActionManagerBuilder,
 )
 from pyface.tasks.i_dock_pane import IDockPane
 from pyface.tasks.i_task_pane import ITaskPane
+from pyface.tasks.i_task_window_backend import ITaskWindowBackend
 from pyface.tasks.task import Task, TaskLayout
-from pyface.tasks.task_window_backend import TaskWindowBackend
 from pyface.tasks.task_window_layout import TaskWindowLayout
 
 # Logging.
@@ -81,7 +83,7 @@ class TaskWindow(ApplicationWindow):
     _active_state = Instance("pyface.tasks.task_window.TaskState")
     _states = List(Instance("pyface.tasks.task_window.TaskState"))
     _title = Str()
-    _window_backend = Instance(TaskWindowBackend)
+    _window_backend = Instance(ITaskWindowBackend)
 
     # ------------------------------------------------------------------------
     # 'Widget' interface.
@@ -403,6 +405,7 @@ def _get_state(self, id_or_task):
     # Trait initializers ---------------------------------------------------
 
     def __window_backend_default(self):
+        from pyface.tasks.task_window_backend import TaskWindowBackend
         return TaskWindowBackend(window=self)
 
     # Trait property getters/setters ---------------------------------------
@@ -448,15 +451,29 @@ class TaskState(HasStrictTraits):
         with an attached Task.
     """
 
+    #: The Task that the state comes from.
     task = Instance(Task)
+
+    #: The layout of panes in the TaskWindow.
     layout = Instance(TaskLayout)
+
+    #: Whether the task state has been initialized.
     initialized = Bool(False)
 
+    #: The central pane of the TaskWindow
     central_pane = Instance(ITaskPane)
-    dock_panes = List(IDockPane)
-    menu_bar_manager = Instance(MenuBarManager)
-    status_bar_manager = Instance(StatusBarManager)
-    tool_bar_managers = List(ToolBarManager)
+
+    #: The list of all dock panes.
+    dock_panes = List(Instance(IDockPane))
+
+    #: The TaskWindow's menu bar manager instance.
+    menu_bar_manager = Instance(IMenuBarManager)
+
+    #: The TaskWindow's status bar instance.
+    status_bar_manager = Instance(IStatusBarManager)
+
+    #: The TaskWindow's tool bar instances.
+    tool_bar_managers = List(Instance(IToolBarManager))
 
     def get_dock_pane(self, id):
         """ Returns the dock pane with the specified id, or None if no such dock
diff --git a/pyface/tasks/tasks_application.py b/pyface/tasks/tasks_application.py
index 9f14443d9..510445098 100644
--- a/pyface/tasks/tasks_application.py
+++ b/pyface/tasks/tasks_application.py
@@ -121,7 +121,7 @@ def create_window(self, layout=None, **kwargs):
 
         Parameters
         ----------
-        layout : TaskLayout instance or None
+        layout : TaskLayout  or None
             The pane layout for the window.
         **kwargs : dict
             Additional keyword arguments to pass to the window factory.
@@ -129,7 +129,7 @@ def create_window(self, layout=None, **kwargs):
 
         Returns
         -------
-        window : ITaskWindow instance or None
+        window : ITaskWindow  or None
             The new TaskWindow.
         """
         from pyface.tasks.task_window_layout import TaskWindowLayout
diff --git a/pyface/tasks/tests/test_api.py b/pyface/tasks/tests/test_api.py
new file mode 100644
index 000000000..048795a57
--- /dev/null
+++ b/pyface/tasks/tests/test_api.py
@@ -0,0 +1,35 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" Test for pyface.api """
+
+import unittest
+
+
+class TestApi(unittest.TestCase):
+    """ Test importable items in any environment."""
+
+    def test_api_importable(self):
+        # make sure api is importable with the most minimal
+        # required dependencies, including in the absence of toolkit backends.
+        from pyface.tasks import api   # noqa: F401
+
+    def test_public_attrs(self):
+        # make sure everything advertised by dir() is available except optional
+        from pyface.tasks import api
+
+        attrs = [
+            name
+            for name in dir(api)
+            if not name.startswith('_')
+        ]
+        for attr in attrs:
+            with self.subTest(attr=attr):
+                self.assertIsNotNone(getattr(api, attr, None))
diff --git a/pyface/tests/test_api.py b/pyface/tests/test_api.py
index 52df08136..abc42b55d 100644
--- a/pyface/tests/test_api.py
+++ b/pyface/tests/test_api.py
@@ -26,6 +26,19 @@ def test_api_importable(self):
         # required dependencies, including in the absence of toolkit backends.
         from pyface import api   # noqa: F401
 
+    def test_public_attrs(self):
+        # make sure everything advertised by dir() is available except optional
+        from pyface import api
+
+        attrs = [
+            name
+            for name in dir(api)
+            if not (name.startswith('_') or name in api._optional_imports)
+        ]
+        for attr in attrs:
+            with self.subTest(attr=attr):
+                self.assertIsNotNone(getattr(api, attr, None))
+
 
 @unittest.skipIf(not is_qt, "This test is for qt.")
 class TestApiQt(unittest.TestCase):
@@ -191,7 +204,6 @@ def test_importable_items(self):
             clipboard,
             confirm,
             error,
-            fix_introspect_bug,
             information,
             warning,
             # Interfaces
diff --git a/pyface/tests/test_array_image.py b/pyface/tests/test_array_image.py
index 479d2a011..79f5560f7 100644
--- a/pyface/tests/test_array_image.py
+++ b/pyface/tests/test_array_image.py
@@ -13,7 +13,8 @@
 
 from traits.testing.optional_dependencies import numpy as np, requires_numpy
 
-from ..array_image import ArrayImage
+if np is not None:
+    from ..array_image import ArrayImage
 
 
 @requires_numpy
diff --git a/pyface/tests/test_system_metrics.py b/pyface/tests/test_system_metrics.py
index fd95d7a9a..2cdc93be0 100644
--- a/pyface/tests/test_system_metrics.py
+++ b/pyface/tests/test_system_metrics.py
@@ -26,6 +26,13 @@ def test_height(self):
         height = self.metrics.screen_height
         self.assertGreaterEqual(height, 0)
 
+    def test_screen_sizes(self):
+        screens = self.metrics.screen_sizes
+        self.assertTrue(all(
+            (isinstance(screen, tuple) and len(screen) == 2)
+            for screen in screens
+        ))
+
     def test_background_color(self):
         color = self.metrics.dialog_background_color
         self.assertIn(len(color), [3, 4])
diff --git a/pyface/timer/api.py b/pyface/timer/api.py
index 1832ca818..d944eafeb 100644
--- a/pyface/timer/api.py
+++ b/pyface/timer/api.py
@@ -27,6 +27,53 @@
 
 """
 
-from .do_later import do_later, do_after, DoLaterTimer
 from .i_timer import ICallbackTimer, IEventTimer, ITimer
-from .timer import CallbackTimer, EventTimer, Timer
+
+
+# ----------------------------------------------------------------------------
+# Deferred imports
+# ----------------------------------------------------------------------------
+
+# These imports have the side-effect of performing toolkit selection
+
+# These are pyface.undo.* imports that have selection as a side-effect
+# TODO: refactor to delay imports where possible
+_relative_imports = {
+    'do_later': 'do_later',
+    'do_after': 'do_later',
+    'DoLaterTimer': 'do_later',
+    'CallbackTimer': 'timer',
+    'EventTimer': 'timer',
+    'Timer': 'timer',
+}
+
+
+def __getattr__(name):
+    """Lazily load attributes with side-effects
+
+    In particular, lazily load toolkit backend names.  For efficiency, lazily
+    loaded objects are injected into the module namespace
+    """
+    # sentinel object for no result
+    not_found = object()
+    result = not_found
+
+    if name in _relative_imports:
+        from importlib import import_module
+        source = _relative_imports[name]
+        module = import_module(f"pyface.timer.{source}")
+        result = getattr(module, name)
+
+    if result is not_found:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+    globals()[name] = result
+    return result
+
+
+# ----------------------------------------------------------------------------
+# Introspection support
+# ----------------------------------------------------------------------------
+
+def __dir__():
+    return sorted(set(globals()) | set(_relative_imports))
diff --git a/pyface/timer/do_later.py b/pyface/timer/do_later.py
index 92e996e88..07f5cc69a 100644
--- a/pyface/timer/do_later.py
+++ b/pyface/timer/do_later.py
@@ -34,7 +34,7 @@ def do_later(callable, *args, **kwargs):
 
     Parameters
     ----------
-    callable : callable
+    callable : Callable
         The callable to call in 50ms time.
     args, kwargs : tuple, dict
         Arguments to be passed through to the callable.
@@ -51,7 +51,7 @@ def do_after(interval, callable, *args, **kwargs):
     ----------
     interval : float
         The time interval in milliseconds to wait before calling.
-    callable : callable
+    callable : Callable
         The callable to call.
     args
         Positional arguments to be passed through to the callable.
diff --git a/pyface/timer/tests/test_api.py b/pyface/timer/tests/test_api.py
new file mode 100644
index 000000000..392dd7e50
--- /dev/null
+++ b/pyface/timer/tests/test_api.py
@@ -0,0 +1,35 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" Test for pyface.api """
+
+import unittest
+
+
+class TestApi(unittest.TestCase):
+    """ Test importable items in any environment."""
+
+    def test_api_importable(self):
+        # make sure api is importable with the most minimal
+        # required dependencies, including in the absence of toolkit backends.
+        from pyface.timer import api   # noqa: F401
+
+    def test_public_attrs(self):
+        # make sure everything advertised by dir() is available except optional
+        from pyface.timer import api
+
+        attrs = [
+            name
+            for name in dir(api)
+            if not name.startswith('_')
+        ]
+        for attr in attrs:
+            with self.subTest(attr=attr):
+                self.assertIsNotNone(getattr(api, attr, None))
diff --git a/pyface/ui/__init__.py b/pyface/ui/__init__.py
index 5cc66c880..002e3d564 100644
--- a/pyface/ui/__init__.py
+++ b/pyface/ui/__init__.py
@@ -37,7 +37,7 @@ class ShadowedModuleLoader(Loader):
     new_name : str
         The full name of the corresponding "real" module.
         Eg. "pyface.ui.qt.foo"
-    new_spec : ModuleSpec instance
+    new_spec : ModuleSpec
         The spec object for the corresponding "real" module.
     """
 
diff --git a/pyface/ui/qt/action/menu_bar_manager.py b/pyface/ui/qt/action/menu_bar_manager.py
index adf6cb7a6..3fefdf028 100644
--- a/pyface/ui/qt/action/menu_bar_manager.py
+++ b/pyface/ui/qt/action/menu_bar_manager.py
@@ -17,13 +17,14 @@
 
 import sys
 
+from traits.api import provides
 
 from pyface.qt import QtGui
-
-
 from pyface.action.action_manager import ActionManager
+from pyface.action.i_menu_bar_manager import IMenuBarManager
 
 
+@provides(IMenuBarManager)
 class MenuBarManager(ActionManager):
     """ A menu bar manager realizes itself in errr, a menu bar control. """
 
diff --git a/pyface/ui/qt/action/menu_manager.py b/pyface/ui/qt/action/menu_manager.py
index 8a1f5641b..d9bf02a61 100644
--- a/pyface/ui/qt/action/menu_manager.py
+++ b/pyface/ui/qt/action/menu_manager.py
@@ -18,15 +18,17 @@
 from pyface.qt import QtCore, QtGui
 
 
-from traits.api import Instance, List, Str
+from traits.api import Instance, List, Str, provides
 
 
 from pyface.action.action_manager import ActionManager
 from pyface.action.action_manager_item import ActionManagerItem
 from pyface.action.action_item import _Tool, Action
+from pyface.action.i_menu_manager import IMenuManager
 from pyface.action.group import Group
 
 
+@provides(IMenuManager)
 class MenuManager(ActionManager, ActionManagerItem):
     """ A menu manager realizes itself in a menu control.
 
diff --git a/pyface/ui/qt/action/status_bar_manager.py b/pyface/ui/qt/action/status_bar_manager.py
index 72492bfde..5c792d8af 100644
--- a/pyface/ui/qt/action/status_bar_manager.py
+++ b/pyface/ui/qt/action/status_bar_manager.py
@@ -17,9 +17,12 @@
 from pyface.qt import QtGui
 
 
-from traits.api import Any, Bool, HasTraits, List, Property, Str
+from traits.api import Any, Bool, HasTraits, List, Property, Str, provides
 
+from pyface.action.i_status_bar_manager import IStatusBarManager
 
+
+@provides(IStatusBarManager)
 class StatusBarManager(HasTraits):
     """ A status bar manager realizes itself in a status bar control. """
 
diff --git a/pyface/ui/qt/action/tool_bar_manager.py b/pyface/ui/qt/action/tool_bar_manager.py
index d60bdb07f..15ad782d1 100644
--- a/pyface/ui/qt/action/tool_bar_manager.py
+++ b/pyface/ui/qt/action/tool_bar_manager.py
@@ -17,13 +17,16 @@
 from pyface.qt import QtCore, QtGui
 
 
-from traits.api import Bool, Enum, Instance, List, Str, Tuple
+from traits.api import Bool, Instance, List, Str, Tuple, provides
 
 
 from pyface.image_cache import ImageCache
 from pyface.action.action_manager import ActionManager
+from pyface.action.i_tool_bar_manager import IToolBarManager
+from pyface.ui_traits import Orientation
 
 
+@provides(IToolBarManager)
 class ToolBarManager(ActionManager):
     """ A tool bar manager realizes itself in errr, a tool bar control. """
 
@@ -42,7 +45,7 @@ class ToolBarManager(ActionManager):
     name = Str("ToolBar")
 
     # The orientation of the toolbar.
-    orientation = Enum("horizontal", "vertical")
+    orientation = Orientation("horizontal")
 
     # Should we display the name of each tool bar tool under its image?
     show_tool_names = Bool(True)
diff --git a/pyface/ui/qt/application_window.py b/pyface/ui/qt/application_window.py
index 5528f5576..bd2d64961 100644
--- a/pyface/ui/qt/application_window.py
+++ b/pyface/ui/qt/application_window.py
@@ -18,17 +18,10 @@
 
 import sys
 
+from traits.api import observe, provides, Str
 
 from pyface.qt import QtGui
-
-
-from pyface.action.api import MenuBarManager, StatusBarManager
-from pyface.action.api import ToolBarManager
-from traits.api import Instance, List, observe, provides, Str
-
-
 from pyface.i_application_window import IApplicationWindow, MApplicationWindow
-from pyface.ui_traits import Image
 from .image_resource import ImageResource
 from .window import Window
 
@@ -39,23 +32,6 @@ class ApplicationWindow(MApplicationWindow, Window):
     IApplicationWindow interface for the API documentation.
     """
 
-    # 'IApplicationWindow' interface ---------------------------------------
-
-    #: The icon to display in the application window title bar.
-    icon = Image()
-
-    #: The menu bar manager for the window.
-    menu_bar_manager = Instance(MenuBarManager)
-
-    #: The status bar manager for the window.
-    status_bar_manager = Instance(StatusBarManager)
-
-    #: DEPRECATED: The tool bar manager for the window.
-    tool_bar_manager = Instance(ToolBarManager)
-
-    #: The collection of tool bar managers for the window.
-    tool_bar_managers = List(ToolBarManager)
-
     # 'IWindow' interface -------------------------------------------------#
 
     #: The window title.
@@ -90,7 +66,7 @@ def _create_status_bar(self, parent):
             status_bar.setVisible(self.status_bar_manager.visible)
 
     def _create_tool_bar(self, parent):
-        tool_bar_managers = self._get_tool_bar_managers()
+        tool_bar_managers = self.tool_bar_managers
         visible = self.control.isVisible()
         for tool_bar_manager in tool_bar_managers:
             # Add the tool bar and make sure it is visible.
@@ -150,18 +126,6 @@ def _create_control(self, parent):
     # Private interface.
     # ------------------------------------------------------------------------
 
-    def _get_tool_bar_managers(self):
-        """ Return all tool bar managers specified for the window. """
-
-        # fixme: V3 remove the old-style single toolbar option!
-        if self.tool_bar_manager is not None:
-            tool_bar_managers = [self.tool_bar_manager]
-
-        else:
-            tool_bar_managers = self.tool_bar_managers
-
-        return tool_bar_managers
-
     # Trait change handlers ------------------------------------------------
 
     # QMainWindow takes ownership of the menu bar and the status bar upon
@@ -177,10 +141,11 @@ def _menu_bar_manager_updated(self, event):
     def _status_bar_manager_updated(self, event):
         if self.control is not None:
             if event.old is not None:
+                self.control.setStatusBar(None)
                 event.old.destroy()
             self._create_status_bar(self.control)
 
-    @observe("tool_bar_manager, tool_bar_managers.items")
+    @observe("tool_bar_managers.items")
     def _update_tool_bar_managers(self, event):
         if self.control is not None:
             # Remove the old toolbars.
@@ -190,7 +155,8 @@ def _update_tool_bar_managers(self, event):
                     child.deleteLater()
 
             # Add the new toolbars.
-            self._create_tool_bar(self.control)
+            if event.new is not None:
+                self._create_status_bar(self.control)
 
     @observe("icon")
     def _icon_updated(self, event):
diff --git a/pyface/ui/qt/code_editor/code_widget.py b/pyface/ui/qt/code_editor/code_widget.py
index 132bdb765..eee2a54ec 100644
--- a/pyface/ui/qt/code_editor/code_widget.py
+++ b/pyface/ui/qt/code_editor/code_widget.py
@@ -844,14 +844,6 @@ def _update_replace_all_enabled(self, text):
 
 if __name__ == "__main__":
 
-    def set_trace():
-        from PyQt4.QtCore import pyqtRemoveInputHook
-
-        pyqtRemoveInputHook()
-        import pdb
-
-        pdb.Pdb().set_trace(sys._getframe().f_back)
-
     app = QtGui.QApplication(sys.argv)
     window = AdvancedCodeWidget(None)
 
diff --git a/pyface/ui/qt/console/console_widget.py b/pyface/ui/qt/console/console_widget.py
index 746aca8fc..9508d24fc 100644
--- a/pyface/ui/qt/console/console_widget.py
+++ b/pyface/ui/qt/console/console_widget.py
@@ -1874,7 +1874,7 @@ def _readline(self, prompt="", callback=None):
         prompt : str, optional
             The prompt to print before reading the line.
 
-        callback : callable, optional
+        callback : Callable, optional
             A callback to execute with the read line. If not specified, input is
             read *synchronously* and this method does not return until it has
             been read.
diff --git a/pyface/ui/qt/data_view/data_view_widget.py b/pyface/ui/qt/data_view/data_view_widget.py
index a240e8a03..e04610540 100644
--- a/pyface/ui/qt/data_view/data_view_widget.py
+++ b/pyface/ui/qt/data_view/data_view_widget.py
@@ -12,10 +12,10 @@
 
 from traits.api import Callable, Enum, Instance, observe, provides
 
-from pyface.qt.QtCore import QAbstractItemModel
-from pyface.qt.QtGui import (
-    QAbstractItemView, QItemSelection, QItemSelectionModel, QTreeView
+from pyface.qt.QtCore import (
+    QAbstractItemModel, QItemSelection, QItemSelectionModel
 )
+from pyface.qt.QtGui import QAbstractItemView, QTreeView
 from pyface.data_view.i_data_view_widget import (
     IDataViewWidget, MDataViewWidget
 )
diff --git a/pyface/ui/qt/fields/combo_field.py b/pyface/ui/qt/fields/combo_field.py
index c2ce4dc16..afb15c1b8 100644
--- a/pyface/ui/qt/fields/combo_field.py
+++ b/pyface/ui/qt/fields/combo_field.py
@@ -19,11 +19,14 @@
 from pyface.fields.i_combo_field import IComboField, MComboField
 from pyface.qt.QtCore import Qt
 from pyface.qt.QtGui import QComboBox
-from .field import Field
+from pyface.ui.qt.util.alignment import (
+    alignment_to_qalignment, qalignment_to_alignment
+)
+from .editable_field import EditableField
 
 
 @provides(IComboField)
-class ComboField(MComboField, Field):
+class ComboField(MComboField, EditableField):
     """ The Qt-specific implementation of the combo field class """
 
     # ------------------------------------------------------------------------
@@ -41,11 +44,6 @@ def _create_control(self, parent):
     # Private interface
     # ------------------------------------------------------------------------
 
-    def _update_value(self, value):
-        """ Handle a change to the value from user interaction
-        """
-        self.value = self._get_control_value()
-
     # Toolkit control interface ---------------------------------------------
 
     def _get_control_value(self):
@@ -101,3 +99,19 @@ def _set_control_values(self, values):
             self._set_control_value(current_value)
         else:
             self._set_control_value(self.value)
+
+    def _get_control_alignment(self):
+        """ Toolkit specific method to get the control's alignment. """
+        # only works if combobox is ieditable, which currently is always False
+        line_edit = self.control.lineEdit()
+        if line_edit is not None:
+            return qalignment_to_alignment(line_edit.alignment())
+        else:
+            # no widget; cheat
+            return self.alignment
+
+    def _set_control_alignment(self, alignment):
+        """ Toolkit specific method to set the control's alignment. """
+        line_edit = self.control.lineEdit()
+        if line_edit is not None:
+            return line_edit.setAlignment(alignment_to_qalignment(alignment))
diff --git a/pyface/ui/qt/fields/editable_field.py b/pyface/ui/qt/fields/editable_field.py
new file mode 100644
index 000000000..0de04eb58
--- /dev/null
+++ b/pyface/ui/qt/fields/editable_field.py
@@ -0,0 +1,37 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The Qt-specific implementation of the text field class """
+
+from traits.api import provides
+
+from pyface.fields.i_editable_field import IEditableField, MEditableField
+from pyface.ui.qt.fields.field import Field
+
+
+@provides(IEditableField)
+class EditableField(MEditableField, Field):
+    """ The Qt-specific implementation of the field class
+
+    This is an abstract class which is not meant to be instantiated. Because
+    many concrete QWidgets provide a `value` property, the default control
+    observer targets this.
+    """
+
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    def _observe_control_value(self, remove=False):
+        """ Toolkit specific method to change the control value observer. """
+        if remove:
+            self.control.valueChanged[int].disconnect(self._update_value)
+        else:
+            self.control.valueChanged[int].connect(self._update_value)
diff --git a/pyface/ui/qt/fields/field.py b/pyface/ui/qt/fields/field.py
index dc3b00aa2..bed8ee3d8 100644
--- a/pyface/ui/qt/fields/field.py
+++ b/pyface/ui/qt/fields/field.py
@@ -15,14 +15,40 @@
 
 from pyface.fields.i_field import IField, MField
 from pyface.ui.qt.layout_widget import LayoutWidget
+from pyface.ui.qt.util.alignment import (
+    alignment_to_qalignment, qalignment_to_alignment
+)
 
 
 @provides(IField)
 class Field(MField, LayoutWidget):
     """ The Qt-specific implementation of the field class
 
-    This is an abstract class which is not meant to be instantiated.
+    This is an abstract class which is not meant to be instantiated.  Because
+    many concrete QWidgets provide a `value` property, the default getters and
+    setters target this.
     """
 
     #: The value held by the field.
     value = Any()
+
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    def _get_control_value(self):
+        """ Toolkit specific method to get the control's value. """
+        return self.control.value()
+
+    def _set_control_value(self, value):
+        """ Toolkit specific method to set the control's value. """
+        self.control.setValue(value)
+
+    def _get_control_alignment(self):
+        """ Toolkit specific method to get the control's alignment. """
+        # default implementation
+        return qalignment_to_alignment(self.control.alignment())
+
+    def _set_control_alignment(self, alignment):
+        """ Toolkit specific method to set the control's alignment. """
+        self.control.setAlignment(alignment_to_qalignment(alignment))
diff --git a/pyface/ui/qt/fields/image_field.py b/pyface/ui/qt/fields/image_field.py
new file mode 100644
index 000000000..04cfc8daf
--- /dev/null
+++ b/pyface/ui/qt/fields/image_field.py
@@ -0,0 +1,52 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The Qt-specific implementation of the text field class """
+
+from pyface.qt.QtGui import QLabel, QPixmap
+
+from traits.api import provides
+
+from pyface.ui.qt.fields.field import Field
+from pyface.fields.i_image_field import IImageField, MImageField
+
+
+@provides(IImageField)
+class ImageField(MImageField, Field):
+    """ The Qt-specific implementation of the image field class
+    """
+
+    # ------------------------------------------------------------------------
+    # IWidget interface
+    # ------------------------------------------------------------------------
+
+    def _create_control(self, parent):
+        """ Create the toolkit-specific control that represents the widget. """
+        control = QLabel(parent)
+        return control
+
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    def _get_control_value(self):
+        """ Toolkit specific method to get the control's value. """
+        # XXX we should really have a ToolkitImage subclass of Image and
+        # which would be the correct subclass to return.
+        return self.control.pixmap()
+
+    def _set_control_value(self, value):
+        """ Toolkit specific method to set the control's value. """
+        if value is None:
+            self._toolkit_value = None
+            self.control.setPixmap(QPixmap())
+        else:
+            self._toolkit_value = self.value.create_bitmap()
+            self.control.setPixmap(self._toolkit_value)
diff --git a/pyface/ui/qt/fields/label_field.py b/pyface/ui/qt/fields/label_field.py
new file mode 100644
index 000000000..8c4ab136b
--- /dev/null
+++ b/pyface/ui/qt/fields/label_field.py
@@ -0,0 +1,49 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The Qt-specific implementation of the label field class """
+
+
+from traits.api import provides
+
+from pyface.fields.i_label_field import ILabelField, MLabelField
+from pyface.qt.QtGui import QLabel, QPixmap
+from .field import Field
+
+
+@provides(ILabelField)
+class LabelField(MLabelField, Field):
+    """ The Qt-specific implementation of the label field class """
+
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    def _create_control(self, parent):
+        """ Create the toolkit-specific control that represents the widget. """
+        control = QLabel(parent)
+        return control
+
+    # Toolkit control interface ---------------------------------------------
+
+    def _get_control_value(self):
+        """ Toolkit specific method to get the control's value. """
+        return self.control.text()
+
+    def _set_control_value(self, value):
+        """ Toolkit specific method to set the control's value. """
+        return self.control.setText(value)
+
+    def _set_control_icon(self, icon):
+        """ Toolkit specific method to set the control's icon. """
+        if icon is not None:
+            self.control.setPixmap(self.icon.create_bitmap())
+        else:
+            self.control.setPixmap(QPixmap())
diff --git a/pyface/ui/qt/fields/spin_field.py b/pyface/ui/qt/fields/spin_field.py
index ce1e52db3..e011d9a12 100644
--- a/pyface/ui/qt/fields/spin_field.py
+++ b/pyface/ui/qt/fields/spin_field.py
@@ -18,11 +18,11 @@
 
 from pyface.fields.i_spin_field import ISpinField, MSpinField
 from pyface.qt.QtGui import QSpinBox
-from .field import Field
+from .editable_field import EditableField
 
 
 @provides(ISpinField)
-class SpinField(MSpinField, Field):
+class SpinField(MSpinField, EditableField):
     """ The Qt-specific implementation of the spin field class """
 
     # ------------------------------------------------------------------------
@@ -39,21 +39,6 @@ def _create_control(self, parent):
     # Private interface
     # ------------------------------------------------------------------------
 
-    def _get_control_value(self):
-        """ Toolkit specific method to get the control's value. """
-        return self.control.value()
-
-    def _set_control_value(self, value):
-        """ Toolkit specific method to set the control's value. """
-        self.control.setValue(value)
-
-    def _observe_control_value(self, remove=False):
-        """ Toolkit specific method to change the control value observer. """
-        if remove:
-            self.control.valueChanged[int].disconnect(self._update_value)
-        else:
-            self.control.valueChanged[int].connect(self._update_value)
-
     def _get_control_bounds(self):
         """ Toolkit specific method to get the control's bounds. """
         return (self.control.minimum(), self.control.maximum())
@@ -61,3 +46,11 @@ def _get_control_bounds(self):
     def _set_control_bounds(self, bounds):
         """ Toolkit specific method to set the control's bounds. """
         self.control.setRange(*bounds)
+
+    def _get_control_wrap(self):
+        """ Toolkit specific method to get whether the control wraps. """
+        return self.control.wrapping()
+
+    def _set_control_wrap(self, wrap):
+        """ Toolkit specific method to set whether the control wraps. """
+        self.control.setWrapping(wrap)
diff --git a/pyface/ui/qt/fields/text_field.py b/pyface/ui/qt/fields/text_field.py
index d5e195511..5675b691a 100644
--- a/pyface/ui/qt/fields/text_field.py
+++ b/pyface/ui/qt/fields/text_field.py
@@ -15,8 +15,7 @@
 
 from pyface.fields.i_text_field import ITextField, MTextField
 from pyface.qt.QtGui import QLineEdit
-from .field import Field
-
+from .editable_field import EditableField
 
 ECHO_TO_QT_ECHO_MODE = {
     "normal": QLineEdit.EchoMode.Normal,
@@ -33,7 +32,7 @@
 
 
 @provides(ITextField)
-class TextField(MTextField, Field):
+class TextField(MTextField, EditableField):
     """ The Qt-specific implementation of the text field class """
 
     #: Display typed text, or one of several hidden "password" modes.
diff --git a/pyface/ui/qt/fields/time_field.py b/pyface/ui/qt/fields/time_field.py
index 0823e9fd2..07d96df2a 100644
--- a/pyface/ui/qt/fields/time_field.py
+++ b/pyface/ui/qt/fields/time_field.py
@@ -17,11 +17,11 @@
 
 from pyface.fields.i_time_field import ITimeField, MTimeField
 from pyface.ui.qt.util.datetime import pytime_to_qtime, qtime_to_pytime
-from .field import Field
+from .editable_field import EditableField
 
 
 @provides(ITimeField)
-class TimeField(MTimeField, Field):
+class TimeField(MTimeField, EditableField):
     """ The Qt-specific implementation of the time field class """
 
     # ------------------------------------------------------------------------
diff --git a/pyface/ui/qt/fields/toggle_field.py b/pyface/ui/qt/fields/toggle_field.py
index fb6b60733..facb5d2f1 100644
--- a/pyface/ui/qt/fields/toggle_field.py
+++ b/pyface/ui/qt/fields/toggle_field.py
@@ -17,11 +17,11 @@
 from pyface.qt.QtGui import (
     QCheckBox, QIcon, QPushButton, QRadioButton
 )
-from .field import Field
+from .editable_field import EditableField
 
 
 @provides(IToggleField)
-class ToggleField(MToggleField, Field):
+class ToggleField(MToggleField, EditableField):
     """ The Qt-specific implementation of the toggle field class """
 
     # ------------------------------------------------------------------------
@@ -60,6 +60,16 @@ def _observe_control_value(self, remove=False):
         else:
             self.control.toggled.connect(self._update_value)
 
+    def _get_control_alignment(self):
+        """ Toolkit specific method to get the control's alignment. """
+        # dummy implementation
+        return self.alignment
+
+    def _set_control_alignment(self, alignment):
+        """ Toolkit specific method to set the control's alignment. """
+        # use stylesheet for button alignment
+        self.control.setStyleSheet(f"text-align: {alignment}")
+
 
 class CheckBoxField(ToggleField):
     """ The Qt-specific implementation of the checkbox class """
diff --git a/pyface/ui/qt/font.py b/pyface/ui/qt/font.py
index 1c0b2a20f..beb21e789 100644
--- a/pyface/ui/qt/font.py
+++ b/pyface/ui/qt/font.py
@@ -187,7 +187,7 @@ def map_to_nearest(target, mapping):
 
     Returns
     -------
-    value : any
+    value : Any
         The value corresponding to the nearest key.  In the case of a tie,
         the first value is returned.
     """
diff --git a/pyface/ui/qt/system_metrics.py b/pyface/ui/qt/system_metrics.py
index 4f230453a..06ade0135 100644
--- a/pyface/ui/qt/system_metrics.py
+++ b/pyface/ui/qt/system_metrics.py
@@ -11,14 +11,10 @@
 # This software is provided without warranty under the terms of the BSD license.
 # However, when used with the GPL version of PyQt the additional terms described in the PyQt GPL exception also apply
 
-
-from pyface.qt import QtGui, is_qt4
-
-
-from traits.api import HasTraits, Int, Property, provides, Tuple
-
+from traits.api import HasTraits, Int, List, Property, provides, Tuple
 
 from pyface.i_system_metrics import ISystemMetrics, MSystemMetrics
+from pyface.qt import QtGui
 
 
 @provides(ISystemMetrics)
@@ -29,10 +25,17 @@ class SystemMetrics(MSystemMetrics, HasTraits):
 
     # 'ISystemMetrics' interface -------------------------------------------
 
+    #: The width of the main screen in pixels.
     screen_width = Property(Int)
 
+    #: The height of the main screen in pixels.
     screen_height = Property(Int)
 
+    #: The height and width of each screen in pixels
+    screen_sizes = Property(List(Tuple(Int, Int)))
+
+    #: Background color of a standard dialog window as a tuple of RGB values
+    #: between 0.0 and 1.0.
     dialog_background_color = Property(Tuple)
 
     # ------------------------------------------------------------------------
@@ -40,26 +43,28 @@ class SystemMetrics(MSystemMetrics, HasTraits):
     # ------------------------------------------------------------------------
 
     def _get_screen_width(self):
-        # QDesktopWidget.screenGeometry() is deprecated and Qt docs
-        # suggest using screens() instead, but screens in not available in qt
-        # see issue: enthought/pyface#721
-        if not is_qt4:
-            return QtGui.QApplication.instance().screens()[0].availableGeometry().width()
+        screens = self.screen_sizes
+        if len(screens) == 0:
+            return 0
         else:
-            return QtGui.QApplication.instance().desktop().availableGeometry().width()
+            return screens[0][0]
 
     def _get_screen_height(self):
-        # QDesktopWidget.screenGeometry(int screen) is deprecated and Qt docs
-        # suggest using screens() instead, but screens in not available in qt
-        # see issue: enthought/pyface#721
-        if not is_qt4:
-            return (
-                QtGui.QApplication.instance().screens()[0].availableGeometry().height()
-            )
+        screens = self.screen_sizes
+        if len(screens) == 0:
+            return 0
         else:
-            return (
-                QtGui.QApplication.instance().desktop().availableGeometry().height()
+            return screens[0][1]
+
+    def _get_screen_sizes(self):
+        screens = QtGui.QApplication.instance().screens()
+        return [
+            (
+                screen.availableGeometry().width(),
+                screen.availableGeometry().height(),
             )
+            for screen in screens
+        ]
 
     def _get_dialog_background_color(self):
         color = (
diff --git a/pyface/ui/qt/tasks/split_editor_area_pane.py b/pyface/ui/qt/tasks/split_editor_area_pane.py
index 9baf03687..889857fc8 100644
--- a/pyface/ui/qt/tasks/split_editor_area_pane.py
+++ b/pyface/ui/qt/tasks/split_editor_area_pane.py
@@ -472,7 +472,7 @@ class EditorAreaWidget(QtGui.QSplitter):
     def __init__(self, editor_area, parent=None, tabwidget=None):
         """ Creates an EditorAreaWidget object.
 
-        editor_area : global SplitEditorAreaPane instance
+        editor_area : global SplitEditorAreaPane
         parent : parent splitter
         tabwidget : tabwidget object contained by this splitter
 
@@ -759,7 +759,7 @@ class DraggableTabWidget(QtGui.QTabWidget):
 
     def __init__(self, editor_area, parent):
         """
-        editor_area : global SplitEditorAreaPane instance
+        editor_area : global SplitEditorAreaPane
         parent : parent of the tabwidget
         """
         super().__init__(parent)
diff --git a/pyface/ui/qt/tests/test_qt_imports.py b/pyface/ui/qt/tests/test_qt_imports.py
index 3327c61a6..821c99de3 100644
--- a/pyface/ui/qt/tests/test_qt_imports.py
+++ b/pyface/ui/qt/tests/test_qt_imports.py
@@ -21,10 +21,13 @@ def test_imports(self):
         import pyface.qt.QtGui  # noqa: F401
         import pyface.qt.QtNetwork  # noqa: F401
         import pyface.qt.QtOpenGL  # noqa: F401
+        import pyface.qt.QtOpenGLWidgets  # noqa: F401
         import pyface.qt.QtSvg  # noqa: F401
+        import pyface.qt.QtSvgWidgets  # noqa: F401
         import pyface.qt.QtTest  # noqa: F401
         import pyface.qt.QtMultimedia  # noqa: F401
         import pyface.qt.QtMultimediaWidgets  # noqa: F401
+        import pyface.qt.QtWidgets  # noqa: F401
 
     @unittest.skipIf(sys.version_info > (3, 6), "WebKit is not available")
     def test_import_web_kit(self):
diff --git a/pyface/ui/qt/util/alignment.py b/pyface/ui/qt/util/alignment.py
new file mode 100644
index 000000000..e9b701664
--- /dev/null
+++ b/pyface/ui/qt/util/alignment.py
@@ -0,0 +1,67 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" Qt alignment helper functions """
+
+from pyface.qt.QtCore import Qt
+
+
+ALIGNMENT_TO_QALIGNMENT = {
+    "default": Qt.AlignmentFlag.AlignLeft | Qt.AlignmentFlag.AlignVCenter,
+    "left": Qt.AlignmentFlag.AlignLeft | Qt.AlignmentFlag.AlignVCenter,
+    "center": Qt.AlignmentFlag.AlignHCenter | Qt.AlignmentFlag.AlignVCenter,
+    "right": Qt.AlignmentFlag.AlignRight | Qt.AlignmentFlag.AlignVCenter,
+}
+QALIGNMENT_TO_ALIGNMENT = {
+    0: "default",
+    int(Qt.AlignmentFlag.AlignLeft): "left",
+    int(Qt.AlignmentFlag.AlignHCenter): "center",
+    int(Qt.AlignmentFlag.AlignRight): "right",
+}
+ALIGNMENT_MASK = (
+    Qt.AlignmentFlag.AlignLeft
+    | Qt.AlignmentFlag.AlignHCenter
+    | Qt.AlignmentFlag.AlignRight
+)
+
+
+def alignment_to_qalignment(alignment):
+    """Convert an Alignment trait value to a Qt Alignment
+
+    Parameters
+    ----------
+    alignment : str
+        An Alignment trait value, one of "default", "left", "center", or
+        "right".
+
+    Returns
+    -------
+    qalignment : Qt.AlignmentFlag
+        A Qt.AlignmentFlag value
+    """
+    return ALIGNMENT_TO_QALIGNMENT[alignment]
+
+
+def qalignment_to_alignment(alignment):
+    """Convert a Qt Alignment value to an Alignment trait
+
+    Parameters
+    ----------
+    qalignment : Qt.AlignmentFlag
+        A Qt.AlignmentFlag value
+
+    Returns
+    -------
+    alignment : str
+        An Alignment trait value, one of "default", "left", "center", or
+        "right".
+    """
+    h_alignment = int(alignment & ALIGNMENT_MASK)
+    return QALIGNMENT_TO_ALIGNMENT[h_alignment]
diff --git a/pyface/ui/qt/util/event_loop_helper.py b/pyface/ui/qt/util/event_loop_helper.py
index a863bf7ac..18676ce08 100644
--- a/pyface/ui/qt/util/event_loop_helper.py
+++ b/pyface/ui/qt/util/event_loop_helper.py
@@ -110,7 +110,7 @@ def event_loop_until_condition(self, condition, timeout=10.0):
 
         Parameters
         ----------
-        condition : callable
+        condition : Callable
             A callable to determine if the stop criteria have been met. This
             should accept no arguments.
 
diff --git a/pyface/ui/qt/util/gui_test_assistant.py b/pyface/ui/qt/util/gui_test_assistant.py
index 12e3bdcec..620cc05b9 100644
--- a/pyface/ui/qt/util/gui_test_assistant.py
+++ b/pyface/ui/qt/util/gui_test_assistant.py
@@ -159,7 +159,7 @@ def event_loop_until_condition(self, condition, timeout=10.0):
 
         Parameters
         ----------
-        condition : callable
+        condition : Callable
             A callable to determine if the stop criteria have been met. This
             should accept no arguments.
         timeout : float
@@ -197,7 +197,7 @@ def assertEventuallyTrueInGui(self, condition, timeout=10.0):
 
         Parameters
         ----------
-        condition : callable() -> bool
+        condition : Callable() -> bool
             Callable accepting no arguments and returning a bool.
         timeout : float
             Maximum length of time to wait for the condition to become
@@ -224,11 +224,11 @@ def assertTraitChangesInEventLoop(
 
         Parameters
         ----------
-        obj : HasTraits
+        obj : traits.has_traits.HasTraits
             The HasTraits instance whose trait will change.
         trait : str
             The extended trait name of trait changes to listen to.
-        condition : callable
+        condition : Callable
             A callable to determine if the stop criteria have been met. This
             takes obj as the only argument.
         count : int
@@ -269,7 +269,7 @@ def event_loop_until_traits_change(self, traits_object, *traits, **kw):
 
         Paramaters
         ----------
-        traits_object : HasTraits instance
+        traits_object : traits.has_traits.HasTraits
             The object on which to listen for a trait events
         traits : one or more str
             The names of the traits to listen to for events
@@ -345,7 +345,7 @@ def find_qt_widget(self, start, type_, test=None):
         type_ : type
             A subclass of QWidget to use for an initial type filter while
             walking the tree
-        test : callable
+        test : Callable
             A filter function that takes one argument (the current widget being
             evaluated) and returns either True or False to determine if the
             widget matches the required criteria.
diff --git a/pyface/ui/qt/util/modal_dialog_tester.py b/pyface/ui/qt/util/modal_dialog_tester.py
index 00782fde3..b4fbf0cdb 100644
--- a/pyface/ui/qt/util/modal_dialog_tester.py
+++ b/pyface/ui/qt/util/modal_dialog_tester.py
@@ -28,7 +28,7 @@
 class ModalDialogTester(object):
     """ Test helper for code that open a traits ui or QDialog window.
 
-    Usage
+    Notes
     -----
     ::
 
@@ -86,7 +86,7 @@ def open_and_run(self, when_opened, *args, **kwargs):
 
         Parameters
         ----------
-        when_opened : callable
+        when_opened : Callable
             A callable to be called when the dialog has been created and
             opened. The callable with be called with the tester instance
             as argument.
@@ -142,7 +142,7 @@ def open_and_wait(self, when_opened, *args, **kwargs):
 
         Parameters
         ----------
-        when_opened : callable
+        when_opened : Callable
             A callable to be called when the dialog has been created and
             opened. The callable with be called with the tester instance
             as argument.
diff --git a/pyface/ui/qt/util/testing.py b/pyface/ui/qt/util/testing.py
index cfdf36368..c35276d97 100644
--- a/pyface/ui/qt/util/testing.py
+++ b/pyface/ui/qt/util/testing.py
@@ -128,7 +128,7 @@ def find_qt_widget(start, type_, test=None):
     type_ : type
         A subclass of QWidget to use for an initial type filter while
         walking the tree
-    test : callable
+    test : Callable
         A filter function that takes one argument (the current widget being
         evaluated) and returns either True or False to determine if the
         widget matches the required criteria.
diff --git a/pyface/ui/qt/workbench/split_tab_widget.py b/pyface/ui/qt/workbench/split_tab_widget.py
index 3536ae13a..83d858ace 100644
--- a/pyface/ui/qt/workbench/split_tab_widget.py
+++ b/pyface/ui/qt/workbench/split_tab_widget.py
@@ -19,8 +19,7 @@
 import sys
 import warnings
 
-
-from pyface.qt import QtCore, QtGui, qt_api
+from pyface.qt import QtCore, QtGui
 
 from pyface.image_resource import ImageResource
 
@@ -300,15 +299,6 @@ def _set_focus(self):
     def _focus_changed(self, old, new):
         """ Handle a change in focus that affects the current tab. """
 
-        # It is possible for the C++ layer of this object to be deleted between
-        # the time when the focus change signal is emitted and time when the
-        # slots are dispatched by the Qt event loop. This may be a bug in PyQt4.
-        if qt_api == "pyqt":
-            import sip
-
-            if sip.isdeleted(self):
-                return
-
         if self._repeat_focus_changes:
             self.focus_changed.emit(old, new)
 
diff --git a/pyface/ui/wx/action/menu_bar_manager.py b/pyface/ui/wx/action/menu_bar_manager.py
index 143d91bac..efe8d8d49 100644
--- a/pyface/ui/wx/action/menu_bar_manager.py
+++ b/pyface/ui/wx/action/menu_bar_manager.py
@@ -15,10 +15,13 @@
 
 import wx
 
+from traits.api import provides
 
 from pyface.action.action_manager import ActionManager
+from pyface.action.i_menu_bar_manager import IMenuBarManager
 
 
+@provides(IMenuBarManager)
 class MenuBarManager(ActionManager):
     """ A menu bar manager realizes itself in errr, a menu bar control. """
 
diff --git a/pyface/ui/wx/action/menu_manager.py b/pyface/ui/wx/action/menu_manager.py
index 2ed052fac..eef36da3f 100644
--- a/pyface/ui/wx/action/menu_manager.py
+++ b/pyface/ui/wx/action/menu_manager.py
@@ -16,14 +16,16 @@
 import wx
 
 
-from traits.api import Str, Bool
+from traits.api import Str, Bool, provides
 
 
 from pyface.action.action_manager import ActionManager
 from pyface.action.action_manager_item import ActionManagerItem
 from pyface.action.group import Group
+from pyface.action.i_menu_manager import IMenuManager
 
 
+@provides(IMenuManager)
 class MenuManager(ActionManager, ActionManagerItem):
     """ A menu manager realizes itself in a menu control.
 
diff --git a/pyface/ui/wx/action/status_bar_manager.py b/pyface/ui/wx/action/status_bar_manager.py
index a268492f5..a766a7778 100644
--- a/pyface/ui/wx/action/status_bar_manager.py
+++ b/pyface/ui/wx/action/status_bar_manager.py
@@ -16,9 +16,12 @@
 import wx
 
 
-from traits.api import Any, HasTraits, List, Property, Str
+from traits.api import Any, HasTraits, List, Property, Str, provides
 
+from pyface.action.i_status_bar_manager import IStatusBarManager
 
+
+@provides(IStatusBarManager)
 class StatusBarManager(HasTraits):
     """ A status bar manager realizes itself in a status bar control. """
 
diff --git a/pyface/ui/wx/action/tool_bar_manager.py b/pyface/ui/wx/action/tool_bar_manager.py
index b2fb60912..41584639f 100644
--- a/pyface/ui/wx/action/tool_bar_manager.py
+++ b/pyface/ui/wx/action/tool_bar_manager.py
@@ -15,15 +15,16 @@
 
 import wx
 
-
-from traits.api import Bool, Enum, Instance, Str, Tuple
-
+from traits.api import Bool, Instance, Str, Tuple, provides
 
 from pyface.wx.aui import aui as AUI
 from pyface.image_cache import ImageCache
 from pyface.action.action_manager import ActionManager
+from pyface.action.i_tool_bar_manager import IToolBarManager
+from pyface.ui_traits import Orientation
 
 
+@provides(IToolBarManager)
 class ToolBarManager(ActionManager):
     """ A tool bar manager realizes itself in errr, a tool bar control. """
 
@@ -42,7 +43,7 @@ class ToolBarManager(ActionManager):
     name = Str("ToolBar")
 
     # The orientation of the toolbar.
-    orientation = Enum("horizontal", "vertical")
+    orientation = Orientation("horizontal")
 
     # Should we display the name of each tool bar tool under its image?
     show_tool_names = Bool(True)
diff --git a/pyface/ui/wx/application_window.py b/pyface/ui/wx/application_window.py
index 659f9c7af..dcac63a49 100644
--- a/pyface/ui/wx/application_window.py
+++ b/pyface/ui/wx/application_window.py
@@ -14,14 +14,9 @@
 
 import wx
 
-from traits.api import Instance, List, Str, observe, provides
-
-from pyface.action.api import MenuBarManager, StatusBarManager
-from pyface.action.api import ToolBarManager
-from pyface.i_application_window import (
-    IApplicationWindow, MApplicationWindow,
-)
-from pyface.ui_traits import Image
+from traits.api import Str, observe, provides
+
+from pyface.i_application_window import IApplicationWindow, MApplicationWindow
 from pyface.wx.aui import aui, PyfaceAuiManager
 from .image_resource import ImageResource
 from .window import Window
@@ -33,30 +28,8 @@ class ApplicationWindow(MApplicationWindow, Window):
     IApplicationWindow interface for the API documentation.
     """
 
-    # 'IApplicationWindow' interface ---------------------------------------
-
-    icon = Image()
-
-    menu_bar_manager = Instance(MenuBarManager)
-
-    status_bar_manager = Instance(StatusBarManager)
-
-    tool_bar_manager = Instance(ToolBarManager)
-
-    # If the underlying toolkit supports multiple toolbars then you can use
-    # this list instead.
-    tool_bar_managers = List(ToolBarManager)
-
     # 'IWindow' interface -------------------------------------------------#
 
-    # fixme: We can't set the default value of the actual 'size' trait here as
-    # in the toolkit-specific event handlers for window size and position
-    # changes, we set the value of the shadow '_size' trait. The problem is
-    # that by doing that traits never knows that the trait has been set and
-    # hence always returns the default value! Using a trait initializer method
-    # seems to work however (e.g. 'def _size_default'). Hmmmm....
-    ##     size = (800, 600)
-
     title = Str("Pyface")
 
     # ------------------------------------------------------------------------
@@ -79,7 +52,7 @@ def _create_status_bar(self, parent):
             self.control.SetStatusBar(status_bar)
 
     def _create_tool_bar(self, parent):
-        tool_bar_managers = self._get_tool_bar_managers()
+        tool_bar_managers = self.tool_bar_managers
         if len(tool_bar_managers) > 0:
             for tool_bar_manager in reversed(tool_bar_managers):
                 tool_bar = tool_bar_manager.create_tool_bar(parent, aui=True)
@@ -174,18 +147,6 @@ def _get_tool_bar_pane_info(self, tool_bar):
 
         return info
 
-    def _get_tool_bar_managers(self):
-        """ Return all tool bar managers specified for the window. """
-
-        # fixme: V3 remove the old-style single toolbar option!
-        if self.tool_bar_manager is not None:
-            tool_bar_managers = [self.tool_bar_manager]
-
-        else:
-            tool_bar_managers = self.tool_bar_managers
-
-        return tool_bar_managers
-
     def _wx_enable_tool_bar(self, tool_bar, enabled):
         """ Enable/Disablea tool bar. """
 
@@ -225,7 +186,7 @@ def _status_bar_manager_changed(self, old, new):
                 old.destroy()
             self._create_status_bar(self.control)
 
-    @observe("tool_bar_manager, tool_bar_managers.items")
+    @observe("tool_bar_managers.items")
     def _update_tool_bar_managers(self, event):
         if self.control is not None:
             self._create_tool_bar(self.control)
diff --git a/pyface/ui/wx/fields/combo_field.py b/pyface/ui/wx/fields/combo_field.py
index 73bf80b2a..9193c6418 100644
--- a/pyface/ui/wx/fields/combo_field.py
+++ b/pyface/ui/wx/fields/combo_field.py
@@ -16,11 +16,11 @@
 from traits.api import provides
 
 from pyface.fields.i_combo_field import IComboField, MComboField
-from .field import Field
+from .editable_field import EditableField
 
 
 @provides(IComboField)
-class ComboField(MComboField, Field):
+class ComboField(MComboField, EditableField):
     """ The Wx-specific implementation of the combo field class """
 
     # ------------------------------------------------------------------------
diff --git a/pyface/ui/wx/fields/editable_field.py b/pyface/ui/wx/fields/editable_field.py
new file mode 100644
index 000000000..6ead41ef8
--- /dev/null
+++ b/pyface/ui/wx/fields/editable_field.py
@@ -0,0 +1,25 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The Wx-specific implementation of the text field class """
+
+
+from traits.api import provides
+
+from pyface.fields.i_editable_field import IEditableField, MEditableField
+from pyface.ui.wx.fields.field import Field
+
+
+@provides(IEditableField)
+class EditableField(MEditableField, Field):
+    """ The Wx-specific implementation of the EditableField class
+
+    This is an abstract class which is not meant to be instantiated.
+    """
diff --git a/pyface/ui/wx/fields/field.py b/pyface/ui/wx/fields/field.py
index d2f484297..8a7f5ee0c 100644
--- a/pyface/ui/wx/fields/field.py
+++ b/pyface/ui/wx/fields/field.py
@@ -11,10 +11,13 @@
 """ The Wx-specific implementation of the text field class """
 
 
-from traits.api import Any, provides
+from traits.api import provides
 
 from pyface.fields.i_field import IField, MField
 from pyface.ui.wx.layout_widget import LayoutWidget
+from pyface.ui.wx.util.alignment import (
+    get_alignment_style, set_alignment_style
+)
 
 
 @provides(IField)
@@ -24,5 +27,17 @@ class Field(MField, LayoutWidget):
     This is an abstract class which is not meant to be instantiated.
     """
 
-    #: The value held by the field.
-    value = Any()
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    def _get_control_alignment(self):
+        """ Toolkit specific method to get the control's read_only state. """
+        return get_alignment_style(self.control.GetWindowStyle())
+
+    def _set_control_alignment(self, alignment):
+        """ Toolkit specific method to set the control's read_only state. """
+        old_style = self.control.GetWindowStyle()
+        new_style = set_alignment_style(alignment, old_style)
+        self.control.SetWindowStyle(new_style)
+        self.control.Refresh()
diff --git a/pyface/ui/wx/fields/image_field.py b/pyface/ui/wx/fields/image_field.py
new file mode 100644
index 000000000..5da484250
--- /dev/null
+++ b/pyface/ui/wx/fields/image_field.py
@@ -0,0 +1,51 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The Qt-specific implementation of the text field class """
+
+from traits.api import provides
+
+from pyface.ui.wx.fields.field import Field
+from pyface.fields.i_image_field import IImageField, MImageField
+from pyface.wx.image_control import ImageControl
+
+
+@provides(IImageField)
+class ImageField(MImageField, Field):
+    """ The Wx-specific implementation of the image field class
+
+    """
+
+    # ------------------------------------------------------------------------
+    # IWidget interface
+    # ------------------------------------------------------------------------
+
+    def _create_control(self, parent):
+        """ Create the toolkit-specific control that represents the widget. """
+        control = ImageControl(parent)
+        return control
+
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    def _get_control_value(self):
+        """ Toolkit specific method to get the control's value. """
+        # XXX we should really have a ToolkitImage subclass of Image and
+        # which would be the correct subclass to return.
+        return self.control.GetBitmap()
+
+    def _set_control_value(self, value):
+        """ Toolkit specific method to set the control's value. """
+        if value is None:
+            self._toolkit_value = None
+        else:
+            self._toolkit_value = self.value.create_bitmap()
+        self.control.SetBitmap(self._toolkit_value)
diff --git a/pyface/ui/wx/fields/label_field.py b/pyface/ui/wx/fields/label_field.py
new file mode 100644
index 000000000..46a69aff4
--- /dev/null
+++ b/pyface/ui/wx/fields/label_field.py
@@ -0,0 +1,47 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" The Wx-specific implementation of the label field class """
+
+import wx
+
+from traits.api import provides
+
+from pyface.fields.i_label_field import ILabelField, MLabelField
+from .field import Field
+
+
+@provides(ILabelField)
+class LabelField(MLabelField, Field):
+    """ The Wx-specific implementation of the label field class """
+
+    def _create_control(self, parent):
+        """ Create the toolkit-specific control that represents the widget. """
+        control = wx.StaticText(parent)
+        return control
+
+    # ------------------------------------------------------------------------
+    # Private interface
+    # ------------------------------------------------------------------------
+
+    # Toolkit control interface ---------------------------------------------
+
+    def _get_control_value(self):
+        """ Toolkit specific method to get the control's value. """
+        return self.control.GetLabel()
+
+    def _set_control_value(self, value):
+        """ Toolkit specific method to set the control's value. """
+        self.control.SetLabel(value)
+
+    def _set_control_icon(self, icon):
+        """ Toolkit specific method to set the control's icon. """
+        # don't support icons on Wx for now
+        pass
diff --git a/pyface/ui/wx/fields/spin_field.py b/pyface/ui/wx/fields/spin_field.py
index 78e02fc47..37ed16bc2 100644
--- a/pyface/ui/wx/fields/spin_field.py
+++ b/pyface/ui/wx/fields/spin_field.py
@@ -19,11 +19,11 @@
 from traits.api import provides
 
 from pyface.fields.i_spin_field import ISpinField, MSpinField
-from .field import Field
+from .editable_field import EditableField
 
 
 @provides(ISpinField)
-class SpinField(MSpinField, Field):
+class SpinField(MSpinField, EditableField):
     """ The Wx-specific implementation of the spin field class """
 
     # ------------------------------------------------------------------------
@@ -65,3 +65,13 @@ def _get_control_bounds(self):
     def _set_control_bounds(self, bounds):
         """ Toolkit specific method to set the control's bounds. """
         self.control.SetRange(*bounds)
+
+    def _get_control_wrap(self):
+        """ Toolkit specific method to get whether the control wraps. """
+        return bool(self.control.GetWindowStyle() & wx.SP_WRAP)
+
+    def _set_control_wrap(self, wrap):
+        """ Toolkit specific method to set whether the control wraps. """
+        if wrap != self._get_control_wrap():
+            self.control.ToggleWindowStyle(wx.SP_WRAP)
+            self.control.Refresh()
diff --git a/pyface/ui/wx/fields/text_field.py b/pyface/ui/wx/fields/text_field.py
index 0f745ccbf..efdf4c6f8 100644
--- a/pyface/ui/wx/fields/text_field.py
+++ b/pyface/ui/wx/fields/text_field.py
@@ -16,11 +16,11 @@
 from traits.api import provides
 
 from pyface.fields.i_text_field import ITextField, MTextField
-from .field import Field
+from .editable_field import EditableField
 
 
 @provides(ITextField)
-class TextField(MTextField, Field):
+class TextField(MTextField, EditableField):
     """ The Wx-specific implementation of the text field class """
 
     # ------------------------------------------------------------------------
diff --git a/pyface/ui/wx/fields/time_field.py b/pyface/ui/wx/fields/time_field.py
index e310c58d0..ce146856f 100644
--- a/pyface/ui/wx/fields/time_field.py
+++ b/pyface/ui/wx/fields/time_field.py
@@ -17,11 +17,11 @@
 from traits.api import provides
 
 from pyface.fields.i_time_field import ITimeField, MTimeField
-from .field import Field
+from .editable_field import EditableField
 
 
 @provides(ITimeField)
-class TimeField(MTimeField, Field):
+class TimeField(MTimeField, EditableField):
     """ The Wx-specific implementation of the time field class """
 
     # ------------------------------------------------------------------------
diff --git a/pyface/ui/wx/fields/toggle_field.py b/pyface/ui/wx/fields/toggle_field.py
index 69209b005..bb025cf64 100644
--- a/pyface/ui/wx/fields/toggle_field.py
+++ b/pyface/ui/wx/fields/toggle_field.py
@@ -15,11 +15,11 @@
 from traits.api import provides
 
 from pyface.fields.i_toggle_field import IToggleField, MToggleField
-from .field import Field
+from .editable_field import EditableField
 
 
 @provides(IToggleField)
-class ToggleField(MToggleField, Field):
+class ToggleField(MToggleField, EditableField):
     """ The Wx-specific implementation of the toggle field class """
 
     # ------------------------------------------------------------------------
diff --git a/pyface/ui/wx/init.py b/pyface/ui/wx/init.py
index bc7c08898..a94f1ead8 100644
--- a/pyface/ui/wx/init.py
+++ b/pyface/ui/wx/init.py
@@ -36,3 +36,7 @@
 if ui_handler is None:
     # Tell the traits notification handlers to use this UI handler
     set_ui_handler(GUI.invoke_later)
+
+# Fix for broken Pycrust introspect module.  Imported to patch pycrust.
+# CJW: is this still needed? Has been in for years.
+from pyface.util import fix_introspect_bug  # noqa: F401, E402
diff --git a/pyface/ui/wx/layout_widget.py b/pyface/ui/wx/layout_widget.py
index 665fa44e0..dce282f31 100644
--- a/pyface/ui/wx/layout_widget.py
+++ b/pyface/ui/wx/layout_widget.py
@@ -94,7 +94,7 @@ def _size_to_wx_size(size):
 
     Returns
     -------
-    wx_size : wx.Size instance
+    wx_size : wx.Size
         A corresponding wx Size instance.
     """
     return wx.Size(*(
@@ -108,7 +108,7 @@ def _wx_size_to_size(wx_size):
 
     Parameters
     ----------
-    wx_size : wx.Size instance
+    wx_size : wx.Size
         A wx Size instance.
 
     Returns
diff --git a/pyface/ui/wx/system_metrics.py b/pyface/ui/wx/system_metrics.py
index 16c308f16..78730b445 100644
--- a/pyface/ui/wx/system_metrics.py
+++ b/pyface/ui/wx/system_metrics.py
@@ -15,12 +15,9 @@
 
 import sys
 
-
 import wx
 
-
-from traits.api import HasTraits, Int, Property, provides, Tuple
-
+from traits.api import HasTraits, Int, List, Property, provides, Tuple
 
 from pyface.i_system_metrics import ISystemMetrics, MSystemMetrics
 
@@ -33,10 +30,17 @@ class SystemMetrics(MSystemMetrics, HasTraits):
 
     # 'ISystemMetrics' interface -------------------------------------------
 
+    #: The width of the main screen in pixels.
     screen_width = Property(Int)
 
+    #: The height of the main screen in pixels.
     screen_height = Property(Int)
 
+    #: The height and width of each screen in pixels
+    screen_sizes = Property(List(Tuple(Int, Int)))
+
+    #: Background color of a standard dialog window as a tuple of RGB values
+    #: between 0.0 and 1.0.
     dialog_background_color = Property(Tuple)
 
     # ------------------------------------------------------------------------
@@ -49,6 +53,9 @@ def _get_screen_width(self):
     def _get_screen_height(self):
         return wx.SystemSettings.GetMetric(wx.SYS_SCREEN_Y)
 
+    def _get_screen_sizes(self):
+        return [(self.screen_width, self.screen_height)]
+
     def _get_dialog_background_color(self):
         if sys.platform == "darwin":
             # wx lies.
diff --git a/pyface/ui/wx/util/alignment.py b/pyface/ui/wx/util/alignment.py
new file mode 100644
index 000000000..589cfe103
--- /dev/null
+++ b/pyface/ui/wx/util/alignment.py
@@ -0,0 +1,41 @@
+# (C) Copyright 2005-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+#
+# Author: Enthought, Inc.
+# Description: <Enthought pyface package component>
+
+""" Utilities for handling alignment """
+
+import wx
+
+
+ALIGNMENT_TO_WX_ALIGNMENT = {
+    'default': wx.TE_LEFT,
+    'left': wx.TE_LEFT,
+    'center': wx.TE_CENTRE,
+    'right': wx.TE_RIGHT,
+}
+WX_ALIGNMENT_TO_ALIGNMENT = {
+    0: 'default',
+    wx.TE_LEFT: 'left',
+    wx.TE_CENTRE: 'center',
+    wx.TE_RIGHT: 'right',
+}
+ALIGNMENT_MASK = wx.TE_LEFT | wx.TE_CENTRE | wx.TE_RIGHT
+
+
+def get_alignment_style(style_flags):
+    alignment_flag = style_flags & ALIGNMENT_MASK
+    return WX_ALIGNMENT_TO_ALIGNMENT[alignment_flag]
+
+
+def set_alignment_style(alignment, style_flags):
+    other_flags = style_flags & ~ALIGNMENT_MASK
+    return other_flags | ALIGNMENT_TO_WX_ALIGNMENT[alignment]
diff --git a/pyface/ui_traits.py b/pyface/ui_traits.py
index e78274123..a968e8ad8 100644
--- a/pyface/ui_traits.py
+++ b/pyface/ui_traits.py
@@ -149,7 +149,7 @@ class PyfaceColor(TraitType):
     """ A Trait which casts strings and tuples to a Pyface Color value.
     """
 
-    #: The default value should be a tuple (factory, args, kwargs)
+    #: The default value should be a tuple (factory, args, kwargs).
     default_value_type = DefaultValue.callable_and_args
 
     def __init__(self, value=None, **metadata):
@@ -161,6 +161,11 @@ def __init__(self, value=None, **metadata):
         super().__init__(default_value, **metadata)
 
     def validate(self, object, name, value):
+        """Validate the trait
+
+        This accepts, Color values, parseable strings and RGB(A) sequences
+        (including numpy arrays).
+        """
         if isinstance(value, Color):
             return value
         if isinstance(value, str):
@@ -182,6 +187,7 @@ def validate(self, object, name, value):
         self.error(object, name, value)
 
     def info(self):
+        """Describe the trait"""
         return (
             "a Pyface Color, a #-hexadecimal rgb or rgba string,  a standard "
             "color name, or a sequence of RGBA or RGB values between 0 and 1"
@@ -225,6 +231,10 @@ def __init__(self, value=None, *, parser=simple_parser, **metadata):
         super().__init__(default_value, **metadata)
 
     def validate(self, object, name, value):
+        """Validate the trait
+
+        This accepts, Font values and parseable strings.
+        """
         if isinstance(value, Font):
             return value
         if isinstance(value, str):
@@ -236,6 +246,7 @@ def validate(self, object, name, value):
         self.error(object, name, value)
 
     def info(self):
+        """Describe the trait"""
         return (
             "a Pyface Font, or a string describing a Pyface Font"
         )
@@ -247,15 +258,18 @@ def info(self):
 
 
 class BaseMB(ABCHasStrictTraits):
-    def __init__(self, *args, **traits):
-        """ Map posiitonal arguments to traits.
+    """ Base class for Margins and Borders
 
-        If one value is provided it is taken as the value for all sides.
-        If two values are provided, then the first argument is used for
-        left and right, while the second is used for top and bottom.
-        If 4 values are provided, then the arguments are mapped to
-        left, right, top, and bottom, respectively.
-        """
+    The constructor of this class maps posiitonal arguments to traits.
+
+    - If one value is provided it is taken as the value for all sides.
+    - If two values are provided, then the first argument is used for
+      left and right, while the second is used for top and bottom.
+    - If 4 values are provided, then the arguments are mapped to
+      left, right, top, and bottom, respectively.
+    """
+
+    def __init__(self, *args, **traits):
         n = len(args)
         if n > 0:
             if n == 1:
@@ -277,32 +291,34 @@ def __init__(self, *args, **traits):
 
 
 class Margin(BaseMB):
+    """A HasTraits class that holds margin sizes."""
 
-    # The amount of padding/margin at the top:
+    #: The amount of padding/margin at the top.
     top = Range(-32, 32, 0)
 
-    # The amount of padding/margin at the bottom:
+    #: The amount of padding/margin at the bottom.
     bottom = Range(-32, 32, 0)
 
-    # The amount of padding/margin on the left:
+    #: The amount of padding/margin on the left.
     left = Range(-32, 32, 0)
 
-    # The amount of padding/margin on the right:
+    #: The amount of padding/margin on the right.
     right = Range(-32, 32, 0)
 
 
 class Border(BaseMB):
+    """A HasTraits class that holds border thicknesses."""
 
-    # The amount of border at the top:
+    #: The amount of border at the top.
     top = Range(0, 32, 0)
 
-    # The amount of border at the bottom:
+    #: The amount of border at the bottom.
     bottom = Range(0, 32, 0)
 
-    # The amount of border on the left:
+    #: The amount of border on the left.
     left = Range(0, 32, 0)
 
-    # The amount of border on the right:
+    #: The amount of border on the right.
     right = Range(0, 32, 0)
 
 
@@ -311,13 +327,13 @@ class HasMargin(TraitType):
         tuple value that can be converted to one.
     """
 
-    # The desired value class:
+    #: The desired value class.
     klass = Margin
 
-    # Define the default value for the trait:
+    #: Define the default value for the trait.
     default_value = Margin(0)
 
-    # A description of the type of value this trait accepts:
+    #: A description of the type of value this trait accepts.
     info_text = (
         "a Margin instance, or an integer in the range from -32 to 32 "
         "or a tuple with 1, 2 or 4 integers in that range that can be "
@@ -371,13 +387,13 @@ class HasBorder(HasMargin):
         or tuple value that can be converted to one.
     """
 
-    # The desired value class:
+    #: The desired value class.
     klass = Border
 
-    # Define the default value for the trait:
+    #: Define the default value for the trait.
     default_value = Border(0)
 
-    # A description of the type of value this trait accepts:
+    #: A description of the type of value this trait accepts.
     info_text = (
         "a Border instance, or an integer in the range from 0 to 32 "
         "or a tuple with 1, 2 or 4 integers in that range that can be "
diff --git a/pyface/util/testing.py b/pyface/util/testing.py
index ce154809f..d55069e8f 100644
--- a/pyface/util/testing.py
+++ b/pyface/util/testing.py
@@ -11,9 +11,15 @@
 import re
 from unittest import TestSuite
 
+try:
+    from importlib.metadata import version
+except:
+    from importlib_metadata import version
+
 from packaging.version import Version
 
-from traits import __version__ as TRAITS_VERSION
+
+TRAITS_VERSION = version("traits")
 
 
 def filter_tests(test_suite, exclusion_pattern):
diff --git a/pyface/wizard/api.py b/pyface/wizard/api.py
index 3f1954541..777b39faa 100644
--- a/pyface/wizard/api.py
+++ b/pyface/wizard/api.py
@@ -27,14 +27,65 @@
 
 """
 
+from .chained_wizard_controller import ChainedWizardController
 from .i_wizard_page import IWizardPage
-from .wizard_page import WizardPage
-
 from .i_wizard import IWizard
-from .wizard import Wizard
-
 from .i_wizard_controller import IWizardController
 from .wizard_controller import WizardController
 
-from .chained_wizard import ChainedWizard
-from .chained_wizard_controller import ChainedWizardController
+
+# ----------------------------------------------------------------------------
+# Deferred imports
+# ----------------------------------------------------------------------------
+
+# These imports have the side-effect of performing toolkit selection
+
+_toolkit_imports = {
+    'Wizard': 'wizard',
+    'WizardPage': 'wizard_page',
+}
+
+# These are pyface.* imports that have selection as a side-effect
+_relative_imports = {
+    'ChainedWizard': "chained_wizard",
+}
+
+
+def __getattr__(name):
+    """Lazily load attributes with side-effects
+
+    In particular, lazily load toolkit backend names.  For efficiency, lazily
+    loaded objects are injected into the module namespace
+    """
+    # sentinel object for no result
+    not_found = object()
+    result = not_found
+
+    if name in _relative_imports:
+        from importlib import import_module
+        source = _relative_imports[name]
+        module = import_module(f"pyface.wizard.{source}")
+        result = getattr(module, name)
+
+    elif name in _toolkit_imports:
+        from pyface.toolkit import toolkit_object
+        source = _toolkit_imports[name]
+        result = toolkit_object(f"wizard.{source}:{name}")
+
+    if result is not_found:
+        raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+    globals()[name] = result
+    return result
+
+
+# ----------------------------------------------------------------------------
+# Introspection support
+# ----------------------------------------------------------------------------
+
+# the list of available names we report for introspection purposes
+_extra_names = set(_toolkit_imports) | set(_relative_imports)
+
+
+def __dir__():
+    return sorted(set(globals()) | _extra_names)
diff --git a/pyface/workbench/action/action_controller.py b/pyface/workbench/action/action_controller.py
index 0d03c8e07..28620553d 100644
--- a/pyface/workbench/action/action_controller.py
+++ b/pyface/workbench/action/action_controller.py
@@ -10,12 +10,12 @@
 """ The action controller for workbench menu and tool bars. """
 
 
-from pyface.action.api import ActionController
+from pyface.action.api import ActionController as PyfaceActionController
 from pyface.workbench.api import WorkbenchWindow
 from traits.api import Instance
 
 
-class ActionController(ActionController):
+class ActionController(PyfaceActionController):
     """ The action controller for workbench menu and tool bars.
 
     The controller is used to 'hook' the invocation of every action on the menu
diff --git a/pyface/wx/image_control.py b/pyface/wx/image_control.py
new file mode 100644
index 000000000..251294178
--- /dev/null
+++ b/pyface/wx/image_control.py
@@ -0,0 +1,59 @@
+# (C) Copyright 2004-2023 Enthought, Inc., Austin, TX
+# All rights reserved.
+#
+# This software is provided without warranty under the terms of the BSD
+# license included in LICENSE.txt and may be redistributed only under
+# the conditions described in the aforementioned license. The license
+# is also available online at http://www.enthought.com/licenses/BSD.txt
+#
+# Thanks for using Enthought open source!
+
+""" Defines a wxPython ImageControl widget that is used by various Widgets.
+"""
+
+
+import wx
+
+
+class ImageControl(wx.Window):
+    """A wxPython control that displays an image.
+    """
+
+    def __init__(self, parent, bitmap=None, padding=10):
+        """Initializes the object."""
+        if bitmap is not None:
+            size = wx.Size(
+                bitmap.GetWidth() + padding, bitmap.GetHeight() + padding
+            )
+        else:
+            size = wx.Size(32 + padding, 32 + padding)
+
+        wx.Window.__init__(self, parent, -1, size=size,)
+        self._bitmap = bitmap
+
+        # Set up the 'paint' event handler:
+        self.Bind(wx.EVT_PAINT, self._on_paint)
+
+    def SetBitmap(self, bitmap=None):
+        """Sets the bitmap image."""
+        if bitmap is not None:
+            if bitmap != self._bitmap:
+                self._bitmap = bitmap
+                self.Refresh()
+        else:
+            self._bitmap = None
+
+    def GetBitmap(self):
+        """Gets the bitmap image."""
+        return self._bitmap
+
+    def _on_paint(self, event=None):
+        """Handles the control being re-painted."""
+        wdc = wx.PaintDC(self)
+        wdx, wdy = self.GetClientSize()
+        bitmap = self._bitmap
+        if bitmap is None:
+            return
+        bdx = bitmap.GetWidth()
+        bdy = bitmap.GetHeight()
+        wdc.DrawBitmap(bitmap, (wdx - bdx) // 2, (wdy - bdy) // 2, True)
diff --git a/pyproject.toml b/pyproject.toml
index b0687a01f..b91cc3c31 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,7 +17,7 @@ dependencies = [
     'importlib-resources>=1.1.0; python_version<"3.9"',
     'traits>=6.2',
 ]
-version = '8.0.0.dev0'
+version = '8.0.0'
 license = {file = "LICENSE.txt"}
 
 [project.entry-points.'pyface.toolkits']
diff --git a/shell_window.png b/shell_window.png
new file mode 100644
index 000000000..12b18a063
Binary files /dev/null and b/shell_window.png differ