Aleph One (formerly known as the Marathon Open Source Project) is a free and open-source first-person shooter engine based on the source code of Bungie Studios' Marathon 2: Durandal. The project commenced in early 2000, when Bungie released the code shortly before being acquired by Microsoft and spurred the fan community to further develop it. Since that time, Aleph One has become a successful project in terms of development and community support. Most modern-day and die-hard Marathon enthusiasts use Aleph One due to its enhancements over the original games and the fact that it is playable with today's platforms. Its name is taken from the second infinite cardinal number in transfinite arithmetic and references Marathon Infinity, the final game in the Marathon Trilogy.
"Major highlights for this release include an entirely new modern 3D renderer option, a plugins system, PNG screenshots, Lua API improvements, and bug fixes." - From Treellama, Aleph One developer
Aleph One 0.23 (2010-01-18) Highlights for this release include a completely new renderer option for Aleph One, written by Clemens Unterkofler and Jeremiah Morris. It supports a modern 3D perspective, parallax bump maps, and bloom. Consequently, you must have some minimal hardware to run it: a Radeon 9500 or GeForce FX5200 or better. To get good frame rates with all features turned on, you will need a modern GPU.
This preview also includes a new plugin system. Installing an Aleph One plugin is as simple as dropping it into the scenario's Plugins directory--you don't even need to unzip it. If you do not have a Plugins directory yet, simply create one. More details, including a brief guide to creating plugins, can be found on the wiki: Source.bungie.org.
The Mac requirements have increased to Mac OS X 10.4 or higher. The Windows version now requires a Pentium II or Athlon processor or better.
This release is network compatible with the previous release, except for new Lua features. However, Rugby scoring has changed, so older releases can't join newer Rugby games and vice versa.