Not really documented.
This is a very old collection of utility functions that I have used in various programs. Its main interest these days is for the functions that read SGI format images, which are used in Crayoland (note - you will still need SGI's libimage, however). For this, just grab the GL-less version.
GL-less version: libdave-nogl.tar.gz
Original, IrisGL version: libdave.tar.gz