- Inside ConTeXt: System Macros (recommended reading), commands, and other programming.
- Implementation reports: select "Development" in Documentation
- LuaTeX documentation
- The Current version
- Git Mirrors at Bitbucket and GitHub
- ConTeXt source browser and its documentation
- Test suite
Comment: There is no official repository where the development is on-going. The source code is released irregularly and placed at the http://www.pragma-ade.com website. The git and source browser repositories are updated by a script from the Current version of the source code.