Cube 2: Sauerbraten is a free multiplayer & singleplayer first person shooter, the successor of the Cube FPS.
Much like the original Cube, the aim of this game is fun, old school deathmatch gameplay and also to allow map/geometry editing to be done
The engine supporting the game is entirely original in code & design, and its code is Open Source (ZLIB license, read the docs for more on how you can use the engine).
Authors, feature list and
the reference documentation or the wiki.
Collect Edition (January 4, 2013):
Download for Windows - 576 MB
Download for Linux - 590 MB
Download for MacOS X - 602 MB
Quadropolis (community site for maps etc.)
SauerDuels (competitive league)
Sauerworld (community blog/news/forum)
sourceforge project page (downloads/subversion)
Cube Server Lister (external browsing app)
Wouter's homepage (developer/designer)
Lee's homepage (developer)