Crafter CMS welcomes your contributions! All of our code is open source and is hosted on GitHub at https://github.com/craftercms. Crafter CMS is written in Java/Groovy and AngularJS. You can also contribute blueprints, and those can be developed in any language and just be backed by Crafter CMS for content.
To get started with making your first contribution, choose a project in GitHub and fork it. Once you finish writing your code simply make a pull request and we’ll help you though the process (review, attribution, etc) of getting your code included in to the development code line of the project. Contributions should be accompanied by any relevant automated tests and documentation.
To learn more about contributing see: https://github.com/craftercms/craftercms/blob/master/CONTRIBUTING.md
Documentation help is greatly appreciated. We use Sphinx-doc to build our documentation using the following high-level template: