The Cocotron is an open source project which aims to implement a cross-platform Objective-C API similar to that described by Apple Inc.'s Cocoa documentation. This includes the AppKit, Foundation, Objective-C runtime and support APIs such as CoreGraphics and CoreFoundation.


The simplest way to contribute code is to create a Mercurial server side clone of the main repository on Google Code and use this for any modifications.

There is a "Create a clone" button here:

The clones allow other Cocotron developers to pull your changes into their clone or the main repository easily and selectively.

Make changes wherever you want, no one "owns" any part of the project, it's all up for grabs, the most appropriate patches are accepted.


  • Make sure your employer, institution, mom, etc. allow you to contribute.
  • Do not contribute code which is not public domain or under the MIT license, regardless of size.
  • Please make sure if the code is from another project that the license and conditions text are exactly the same, some projects say they use the MIT license but do not use the same text. Please reference the originating project in the contribution.
  • By submitting your own code you are automatically agreeing that the code is to be placed under the MIT license and to become part of the project.

What else you can contribute

  • Any source code which you think will help the project, in any reasonable form.
  • Reference to other public domain or MIT licensed software which may be helpful to the project.
  • Behavioral descriptions which supplement the Apple documentation.

What to expect

  • All changes are reviewed and put in as soon as possible.
  • If the change has not been integrated into a recent version of the source, expect it to take a long time to get in as someone will have to do work to integrate it. That is OK, just don't expect it to go in quickly.
  • There is no guarantee that your contribution will be merged into the main repository.

Periodically I will update the credits with contributors who have made a significant quantity of changes, please don't take offense if you don't get credited right away, it'll happen.