Crystal Space-A good 3d game engine. Still in
development. Has a great 3d engine though. They have indoors
and they are going to add in a outdoor engine and a landscape
engine. This is under the LGPL.
Panard Vision-A free SDK for making 3d
games. We were mostly looking at this because it is already
done.
WorldFoundry-A pretty good looking 3D engine, and level
editor
