See the manual page for LIBFB supplied with the BRL-CAD distribution or:

M. J. Muuss, ``Workstations, Networking, Distributed Graphics, and Parallel Processing'' in Computer Graphics Techniques: Theory and Practice, ed. D. F. Rogers, R. A. Earnshaw, Springer-Verlag, 1990.

Also in ``The Ballistic Research Laboratory CAD Package Release 4.0 Manuals, Volume V, Analyst's Manual'' Page V5S06A02.

for more information about the framebuffer support library in general.