Modelled somewhat on the API of Qt4 from Nokia/Trolltech, Zut is LPGL licensed, thoroughly unit tested (with CppUnit) and actively used.
The project is split into several libraries, as follows: ZutCore: timing (sleep, current system time, UTC time, elapsed time) and debugging (debugging levels, compile out debug messages, assertions). ZutOpenGL: simple GLut application base class.
Headers are included like:
Zut source can be found at http://repo.or.cz/w/zut.git where it is stored under git.
Use Patent Claims
Include Install Instructions