It contains mostly code written by me, with some classes copied or inspired by other people. Credits on particular files and on the main readme.
It also includes ugl the micro game library (I call it ugly), that I use for rapid game prototyping. Ugl was originally based on mgl, but things have drifted apart pretty fast plus I have a non-cryptic name convention.
There is a bunch of code and very little documentation so far. I plan to improve this in the future, but who knows.
Go check it out.