Space War 98
  A two-player game like asteroid with planets and gravity.

VampBeta 0.1
  A cross between cannon fodder and dune2 and warcraft.

Border Wars
  Direct X 5 3D engine. Should be compatible with a lot of D3D accelerators.

KickA$$ 3D Engine Ver 1.00 (DirectX6)
  Does heaps of cool stuff, featuring Carmageddon2 level and car. Up for 3d hardware compatibility testing. Test it on your card now!

Mountain Fly-around Demo
  DOS 3D engine. Run in true Win32 and DOS. Doesn't require 3D accelerator, but fast 2D card helps.

Environment Mapping Demo
  DOS 3D engine. Run in true DOS mode only. Doesn't require 3D accelerator, but fast 2D card helps.

LINX

DeFy Productions
  web page

Overlord's Coding page
  (old)

Marshall
  amplification page.