This software is by David Medine. It is totally free, totally useless, or useful. There is no warranty and no license. This is a C library for doing matrix stuff that you need for openGL programs. It emulates the most commonly used functionality of GLM, which is in C++. The functions it has are rotate, translate, lookAt and perspective. This is so small, but I decided to package it up as a static library. Build the example program (which is a C version of the C++ tutorial on openGL that you can find here: http://en.wikibooks.org/wiki/OpenGL_Programming/Modern_OpenGL_Tutorial_05) by typing : make The library libgslu.a will build automatically. cd into the lib directory and hit make if you just want that. If you have openGL and GSL installed, it should work just fine, although you may need to add/change the includes in the makefiles so that they are right. I put in the standard ones. Once the library is build, just include the path the the gsl_utilities.h in your C programs and you should be good to go.