from Hacker News

Sage is a simple and flexible documentation generator for PHP code. It outputs basic API documentation in markdown format suitable for projects which use GitHub, but most other markdown tools should be able to parse and format it properly.

This is extremely well suited for creating API documentation that can be browsed and and is visible in your source tree on GitHub.

Also, because it uses markdown, you can format your docblock comments in markdown for very richly formatted documentation with ease of use!

To learn more about Sage, visit:

https://github.com/dotink/Sage

To see an example of some generated documentation, check out:

https://github.com/dotink/Sage/blob/master/external/docs/classes/Dotink/Sage/TokenParser/TokenParam.md