The Collective Code Construction Contract (C4) is an evolution of the github.com [http://help.github.com/send-pull-requests/ Fork + Pull Model], aimed at providing an optimal collaboration model for free software projects. This is a modified version of revision 1 of the C4 specification. The original C4.1 specification can be found here: http://rfc.zeromq.org/spec:22.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [http://tools.ietf.org/html/rfc2119 RFC 2119].
C4 is meant to provide a reusable optimal collaboration model for open source software projects. It has these specific goals:
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To maximize the scale of the community around a project, by reducing the friction for new Contributors and creating a scaled participation model with strong positive feedbacks;
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To relieve dependencies on key individuals by separating different skill sets so that there is a larger pool of competence in any required domain;
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To allow the project to develop faster and more accurately, by increasing the diversity of the decision making process;
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To support the natural life cycle of project versions from experimental through to stable, by allowing safe experimentation, rapid failure, and isolation of stable code;
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To reduce the internal complexity of project repositories, thus making it easier for Contributors to participate and reducing the scope for error;
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To enforce collective ownership of the project, which increases economic incentive to Contributors and reduces the risk of hijack by hostile entities.
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The project SHALL use the git distributed revision control system.
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The project SHALL be hosted on github.com, herein called the "Platform".
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The project SHALL use the Platform issue tracker.
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The project SHOULD have clearly documented guidelines for code style.
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A "Contributor" is a person who wishes to provide a patch, being a set of commits that solve some clearly identified problem.
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A "Maintainer" is a person who merge patches to the project. Maintainers are not developers; their job is to enforce process.
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Contributors SHALL NOT have commit access to the repository unless they are also Maintainers.
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Maintainers SHALL have commit access to the repository.
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Everyone, without distinction or discrimination, SHALL have an equal right to become a Contributor under the terms of this contract.
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The project SHALL use Apache License, Version 2.0.
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All contributions to the project source code ("patches") SHALL use the same license as the project.
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All patches are owned by their authors. There SHALL NOT be any copyright assignment process.
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The copyrights in the project SHALL be owned collectively by all its Contributors.
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Each Contributor SHALL be responsible for identifying themselves in the project Contributor list. (See
AUTHORS.txt
.)
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Maintainers and Contributors MUST have a Platform account and SHOULD use their real names or a well-known alias.
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A patch SHOULD be a minimal and accurate answer to exactly one identified and agreed problem.
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A patch MUST adhere to the code style guidelines of the project if these are defined.
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A patch MUST adhere to the "Evolution of Public Contracts" guidelines defined below.
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A patch SHALL NOT include non-trivial code from other projects unless the Contributor is the original author of that code.
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A patch MUST compile cleanly and pass project self-tests on at least the principle target platform.
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A patch commit message SHOULD consist of a single short (less than 50 character) line summarizing the change, optionally followed by a blank line and then a more thorough description.
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A "Correct Patch" is one that satisfies the above requirements.
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Change on the project SHALL be governed by the pattern of accurately identifying problems and applying minimal, accurate solutions to these problems.
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To request changes, a user SHOULD log an issue on the project Platform issue tracker.
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The user or Contributor SHOULD write the issue by describing the problem they face or observe.
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The user or Contributor SHOULD seek consensus on the accuracy of their observation, and the value of solving the problem.
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Users SHALL NOT log feature requests, ideas, suggestions, or any solutions to problems that are not explicitly documented and provable.
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Thus, the release history of the project SHALL be a list of meaningful issues logged and solved.
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To work on an issue, a Contributor SHALL fork the project repository and then work on their forked repository.
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To submit a patch, a Contributor SHALL create a Platform pull request back to the project.
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A Contributor SHALL NOT commit changes directly to the project.
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If the Platform implements pull requests as issues, a Contributor MAY directly send a pull request without logging a separate issue.
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To discuss a patch, people MAY comment on the Platform pull request, on the commit, or elsewhere.
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To accept or reject a patch, a Maintainer SHALL use the Platform interface.
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Maintainers SHOULD NOT merge their own patches except in exceptional cases, such as non-responsiveness from other Maintainers for an extended period (more than 1-2 days).
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Maintainers SHALL NOT make value judgments on correct patches.
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Maintainers SHALL merge correct patches from other Contributors rapidly.
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The Contributor MAY tag an issue as "Ready" after making a pull request for the issue.
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The user who created an issue SHOULD close the issue after checking the patch is successful.
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Maintainers SHOULD ask for improvements to incorrect patches and SHOULD reject incorrect patches if the Contributor does not respond constructively.
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Any Contributor who has value judgments on a correct patch SHOULD express these via their own patches.
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Maintainers MAY commit changes to non-source documentation directly to the project.
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The project SHALL have one branch ("master") that always holds the latest in-progress version and SHOULD always build.
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The project SHALL NOT use topic branches for any reason. Personal forks MAY use topic branches.
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To make a stable release someone SHALL fork the repository by copying it and thus become maintainer of this repository.
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Forking a project for stabilization MAY be done unilaterally and without agreement of project maintainers.
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A stabilization project SHOULD be maintained by the same process as the main project.
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A patch to a stabilization project declared "stable" SHALL be accompanied by a reproducible test case.
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All Public Contracts (APIs or protocols) SHOULD be documented.
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All Public Contracts SHOULD have space for extensibility and experimentation.
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A patch that modifies a stable Public Contract SHOULD not break existing applications unless there is overriding consensus on the value of doing this.
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A patch that introduces new features to a Public Contract SHOULD do so using new names.
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Old names SHOULD be deprecated in a systematic fashion by marking new names as "experimental" until they are stable, then marking the old names as "deprecated".
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When sufficient time has passed, old deprecated names SHOULD be marked "legacy" and eventually removed.
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Old names SHALL NOT be reused by new features.
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When old names are removed, their implementations MUST provoke an exception (assertion) if used by applications.
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The project founders SHALL act as Administrators to manage the set of project Maintainers.
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The Administrators SHALL ensure their own succession over time by promoting the most effective Maintainers.
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A new Contributor who makes a correct patch SHALL be invited to become a Maintainer.
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Administrators MAY remove Maintainers who are inactive for an extended period of time, or who repeatedly fail to apply this process accurately.
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[http://en.wikipedia.org/wiki/Chris_Argyris Argyris' Models 1 and 2] - the goals of C4.1 are consistent with Argyris' Model 2.
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[http://en.wikipedia.org/wiki/Toyota_Kata Toyota Kata] - covering the Improvement Kata (fixing problems one at a time) and the Coaching Kata (helping others to learn the Improvement Kata).