3D Clipping for Realtime Graphics
1997 tutorial on 3D graphics clipping.

Color Conversion Algorithms
Converting between RGB, HSV, etc. color types.

Computational Geometry
ICS 161: Design and Analysis of Algorithms Lecture notes for March 7, 1996

Cubic Team Demos
Demo group page from the early 1990s with demos and sources.

Flipcode
Closed its doors in 2005 but the archives are still available. Previously a popular website for 3d graphics and game programming.

Gamasutra
Game development site.

Gamedev
Large game development site.

Gamespot
Games discussion.

Graphics File Format Page
Several graphics file formats.

Hornet
Archive for the PC Demoscene.

Wacky World of Advanced Graphics
Quake 3D engine tutorials from the late 1990s.