This is Gauche-gl, Gauche Graphics Library.

See INSTALL (English) or INSTALL.utf-8 (Japanese) for
installation instructions.

Under doc/, you can find texinfo file of the documentation.
It is incomplete but may be of some use.

Under win32/, there are some auxiliary libraries required for
win32 platform.   Things under this directory has its own
copyright notices; check each subdirectories.

It contains freeglut-3.0.0-1, a precompiled binary
of Pawel W. Olszta's FreeGlut, build for MinGW by Transmission Zero.
The package can be obtained from:
http://www.transmissionzero.co.uk/software/freeglut-devel/