These are Steve Baker 's portability libraries. They are licensed under the LGPL. From the README: The following libraries are provided: JS -- A Joystick interface. PUI -- A simple GUI built on top of OpenGL. SG -- Some Standard Geometry functions (vector and matrix math, spheres, boxes, frustra, etc) SL -- A Games-oriented Sound Library. SSG -- A Simple Scene Graph API built on top of OpenGL. WWW: http://plib.sourceforge.net/ - Brian Buchanan brian@CSUA.Berkeley.EDU