More info on www.crystalspace.org
For Developers: Crystal space project homepage on SourceForge.
You can make simple maps with it. More info..
Here are some newer screenshots
Download:
Supported versions: 0.97(CVS)(maybe 0.96R004- not tested)
--OUTDATED-- will not work with current CVS and Releases of CS!
I have made a plugin for CS that will decode AVI's via Windows VFS library. More info..