My attempt to reverse engineer the iOS Nib format (used for storing compiled interface files) and create a tool to do similar things as Apple's ibtool.
Currently, ibtool supports only compiling XIB and storyboard files and printing NIB files in a readable way. (Only works with Interface Builder documents for iOS, not OS X.)
Usage: ibtool.py [OPTIONS] input-file
--dump dump the contents of a NIB file in a readable format
--compile <output pathname> compile a XIB or storyboard file to a binary format
-e show type encodings when dumping a NIB file
If no command is specified, ibtool will assume --dump,
i.e. ibtool.py --dump somefile.nib and ibtool.py somefile.nib are equivalent.
The set of Interface Builder features supported by this application is very limited, and requires specific functionalities to be manually added, so certain usages of unimplemented views, scenes, layout constraints, or size classes may fail to compile or result in NIBs that are missing functionality.