FlashMesa3D is a project mainly written in C and C++, it's free.
A Flash port of Mesa3D, using Adobe Alchemy.
An uncompleted Flash port of Mesa3D.
By Ed McManus.
Follow me on Twitter!
http://www.twitter.com/emcmanus
To start exploring this project, take a look at src/c/mesa3d/Makefile
This should give you some idea of which files to explore next. If you want any more pointers feel free to message me!