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.

Post download Report content Aleph One 0.23 Windows
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Feb 18th, 2010
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"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:

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.


  • OpenGL (Shader) renderer
    • Bloom (when enabled) is applied automatically to self-luminescent colors (such as Pfhor fighter staff crystals) and glow maps
    • Additional bloom on textures and landscapes can be enabled with MML (see MML.html)
    • Supports bump maps with normals in RGB channels and height in alpha channel (see MML.html)
    • Shaders are customizable using MML (see MML.html)
    • Plugins for extra bloom, bump maps, and custom shaders will be available on Fileball and Simplici7y
  • Masking support for enhanced Lua HUDs (see Lua_HUD.html)
  • Zipped plugins support
  • Screenshot improvements
    • Screenshots are now saved as PNG
    • Screenshots are saved in a Screenshots folder in prefs
    • In-game screenshots are named for the level they were taken on
    • In-game screenshots include metadata for X, Y, Z, facing, polygon, map pack
  • Lua Improvements (see Lua.html)
    • monster_damaged trigger
    • speed unit documentation
    • accessors for Platforms.type, .door, and .locked
    •, .initial_phase, .initially_active, .intensity, .states
    • Media.direction, .height, .high, .light, .low, .speed, .type
    • Game.proper_item_accounting
  • Double the available number of map indexes (prevents crashes on very complex maps)
  • Mac OS X: Add a 64-bit Intel executable (requires Snow Leopard)

Bug Fixes

  • Don't crash trying to render a texture palette bitmap that doesn't exist
  • Increase the maximum sounds that can be loaded at once; with 4 channels, use as much memory as Marathon 2 did. With 32 channels, use eight times that much
  • Reset the map file after playing from a saved game
  • Fix bug 2893933 (respawning in faux netgame)
  • Prevent hosting with nonexistent map file
  • Enable media fader based on chase-cam position
  • Work around for 2894880 (weird Rugby behavior/crash when ball is picked up in goal)
  • Fix bug 1605895 (level specific MML can't set scenery solidity consistently)
  • Don't overwrite alternate color table flags with primary color table flags (makes projectile fighter crystals self-luminescent as marked)
  • Change Rugby scoring to first-to-n when score limit is selected, rather than best-of-n; matches CTF scoring
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Aleph One 0.23 Windows
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Varsity Feb 19 2010 says:

They don't tell you here, but you also need to download Marathon's data files from . Extract the files to the same folder as AlephOne.exe.

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