GLE is known to run on UNIX(r) and UNIX-like operating systems such as Linux, AIX, IRIX, Ultrix and HPUX with OpenGL or Mesa. GLE is also known to run on OS/2 Warp.
This walk the src directory, and build two libraries, libmatrix.a and libgle.a. It should then move on and build the demo directory, linking in the above libraries and libglut.a. Finally, this will run the demos in the demo directory.
If you have difficulties... here are some notes:
(Warning: the library has NOT been run on GL 3.2 in years, and so might be broken in minor ways. With tweaking, though it should work.)
The demos require that the GLUT windowing and utility library be installed. GLU can be obtained at http://www.sgi.com/Technology/openGL/glut.html
(In my humble opinion, the way in which the C/C++ language handles doubly, triply, etc. subscripted arrays is fundamentally broken. The syntax is not self-consistent. Many important constructs are undefined by ANSI-C (and C++). In the good old days, when most compilers were broken in this area anyway, you could happily work around this with single-index arrays and fancy address calculation. Now that compilers have been fixed, and, thanks to C++, strict-type-checking is all the rage, the fundamental short-comings of C/C++ in this area start becoming horribly apparent.
To put it another way, I agonized over how subscripting should be handled, and what, if any new types needed to be introduced. Sadly, I was unable to design code that compiled on most compilers, AND not introduce new types, AND avoid strict-typechecking warning messages. Sadly, the result is a horrible mess. )
To hack textures, read the documentation, then look at texgen.c