From Quake Wiki

Author: mh
Based on: GLQuake
First release: here
Newest release: here
Website: here

A port of GLQuake to Direct3D with emphasis on bug fixes, being faithful to the original software Quake look, increased limits, and player-friendliness.

This is primarily intended for use on PCs and laptops that have integrated Intel 3D cards which either choke on, or give incredibly poor performance with, OpenGL-based Quake engines. It is also suitable for more general use on any machine, of course.