Overview
OpenGL is a library of functions for fast 3D rendering.
What OpenGL is not
OpenGL does not have any way to obtain input from the user. In order to
do this you must use XLib calls or some sort of toolkit like Tcl/Tk or
Motif.
Additional libraries
There are two libraries that we have that came with OpenGL. One is
glu and the other is glX.
glu is a set of utility functions. They are easy ways of doing
things that are tedious with raw OpenGL.
glX allows you to open up an X Window and link it up with OpenGL
so that it will draw to that window.