Sid Meier's Alpha Centauri (GLSMAC)

Games: Sid Meier's Alpha Centauri (Windows, 1999) · Sid Meier's Alpha Centauri: Alien Crossfire → (Windows, 1999)

GLSMAC: a free reimplementation of Sid Meier’s Alpha Centauri and its Alien Crossfire expansion, written from scratch in C++ with OpenGL and SDL2, that loads the images, sounds, and other resources from your installed copy of the game. It doesn’t disassemble the original executables or link to their libraries. It aims to replicate the original game, with its models, texts, factions, and rules, but rewrites the graphics engine and the network code, which won’t be compatible with the original’s; map generation, AI, and dynamic music are recreated from scratch. It already has a random map generator, most of the interface, a map editor, and, since v0.3, a multiplayer lobby for hosting and joining games, with chat. The game logic and interface are written in moddable JavaScript-like scripts (.gls.js). The game itself is still under construction: the 2026 work, on the way to v0.4, focuses on bases (production, facilities, and worked tiles). There are 64-bit builds for Windows and Ubuntu; the latest stable one is v0.3-db4dbc9 (May 31), and development builds are kept up to date. It builds on macOS but crashes because of OpenGL issues. Its author states that they don’t use AI-generated code, though they accept contributions made with it: three commits by one contributor declare it, one of them listing Claude as a co-author.

You needYour own copy of Sid Meier’s Alpha Centauri with the Alien Crossfire expansion installed; the GOG, Steam (Planetary Pack), Loki, and Legacy releases are supported. On first launch it asks for the game folder. Plus 64-bit Windows or Linux and, for 60 fps, a graphics card along the lines of an Intel HD 4400, Radeon R7, or GeForce GT 710, with 2–4 GB of RAM.

How it gets to PC

Fan reimplementation

Console

Microsoft Windows

Original studio

Firaxis Games

Year

1999

Author

afwbkbc

Stars

648

Last activity

2026-10-21 · 10 days ago

Latest version

v0.3-db4dbc9 · 2026-05-31

License

AGPL-3.0

Language

C++

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