Updated: 12/29/2005
Game-Q2
Blur Engine
A Quake 2 engine. Probably requires original full Q2 game and OpenGL. [Report a dead link]
http://www.planetquake.com/blur/news.html

Quake 2 Evolved
Another Q2 engine. Probably requires full Q2 game and OpenGL. Also requires OpenAL for audio. [Report a dead link]
http://www.planetquake.com/blur/files_q2e.html