Aleph One is a game engine currently in development by the Open Source community. It is based on the source code of Marathon 2: Durandal, a game created by Bungie Software in 1995. Since Bungie released the source code, Aleph One has matured to include a variety of new features and improvements.

http://dl.openhandhelds.org/cgi-bin/wiz.cgi?0,0,0,0,30,266