Is Marathon 2 really free?

Yes. Bungie permitted the Marathon trilogy's game data to be distributed at no cost, and the Aleph One engine that runs it is open source under the GPL. The download includes both — there is nothing to buy and no original copy required.

Aleph One is the open-source continuation of Bungie's Marathon 2 engine, maintained since Bungie released the source code in 2000. It adds modern resolutions, mouselook, OpenGL rendering and network play, and is what makes the games run on current machines.

Should I play Marathon 1 first?

Not necessarily. Marathon 2 is the usual starting point — it is the strongest of the three and its story stands on its own. The first game is also free if you want the full arc afterwards.

Does it work on modern Windows, Mac and Linux?

Yes, with native builds for all three, including Apple Silicon. There is no emulator or compatibility layer involved.

Is there still multiplayer?

Yes, Aleph One supports internet and LAN play, though the population is small and organised through community channels rather than matchmaking. Treat this as a single-player game with multiplayer available, not the other way round.

Can I play it on Steam Deck?

Yes. It is extremely light on hardware and works well with a gamepad configuration, though a mouse remains the better way to aim.

Marathon 2 — Free FPS

25 MB

Releases

GitHub Release8/29/2025

Aleph One 1.11

This release is not network compatible with the previous release, and films saved with this release cannot be played back with older releases. Highlights: + Native Steam Linux support + Audio improvements + Additional sprite rendering option for 3D perspective + Replay films for saved games Changes: + Numerous audio improvements: + Pauses/resumes in-game audio when the game is paused/resumed + Intro music now continues to play in preferences dialogs + Shield/O2 charger now fully loop to prevent pops + Adds 3D spatialization for stereo sources + HRTF no l

GitHub Release8/8/2025

Aleph One 1.11b

Please help test this beta release. It is not network compatible with the previous release, and films cannot be played back with older releases. Highlights: + Native Steam Linux support. To test the native Linux beta on Steam, you will need beta keys. Post in [this thread](https://steamcommunity.com/app/2398450/discussions/0/598534283538470240/) and we will send keys by PM. + Audio improvements + Additional sprite rendering option for 3D perspective + Replay films for saved games Changes: + Numerous audio improvements: + Pauses/resumes in-game audio when the game is paused/

GitHub Release3/3/2025

Aleph One 1.10.1

This is a bug fix release. Highlights: * Uses HUD filtering preference for Lua HUD images * Physics file is no longer mandatory for gathering using dedicated servers * It is now possible to mix workshop scenarios and local scenarios in the Steam version of Classic Marathon Infinity * Fixes an issue interpolating ephemera

GitHub Release8/22/2024

Aleph One 1.10

Along with support for Classic Marathon Infinity on Steam and an uploader for the Steam Workshop, this release also includes a new scenario chooser. To use the scenario chooser, place the Aleph One executable in a folder containing scenario folders, or add a "Scenarios" folder to one of the original trilogy folders. The scenario chooser is not included with all-in-one Mac apps; use the standalone Aleph One app instead.

GitHub Release7/12/2024

Aleph One 1.9

This is a major release featuring support for [Classic Marathon 2 on Steam](https://store.steampowered.com/app/2398490/Classic_Marathon_2/), dedicated servers, ping times for metaserver net games, a pregame network loading screen, automatic demos, and more authentic gameplay options. Aleph One 1.9 is not backwards compatible with Aleph One 1.8 net games. Changes: * Classic Marathon 2 with achievements on Steam * Dedicated servers It is now possible to gather multiplayer or co-op games without any router configuration. The netgame setup process is the same, but selecting the Use