Mac OS 9
Mac OS 9 API Documentation

Docs generated from the header files that were given for developers wanting to develop for Classic Mac OS. It's actually so recent that it's not even for Classic Mac OS; it's for Carbon developers. However, the functions that were removed in Carbon were left in, making it suitable for 9.2.2.

Currently the documentation is straight from Apple, who was apparently not very good at documenting things. The goal is for me and hopefully others to learn more about the API and fill in the gaps, to create a better documentation.

Source code avaliable here.