QuakeSpasm

QuakeSpasm is a stable, open‑source engine that runs the original Quake game created by id Software. It reimplements the game’s core functionality using C and OpenGL, and relies on SDL for cross‑platform input and window handling. The engine is designed to be compatible with the classic Quake data files, allowing users to launch and play the game on modern systems.

Target users are enthusiasts who want to experience Quake with a lightweight, maintained codebase that supports macOS and other platforms. Developers and modders can also use the engine as a reference implementation for studying the original game’s architecture or for building extensions that work with the existing Quake data format.

What distinguishes QuakeSpasm is its focus on faithfully reproducing the original gameplay while using contemporary graphics and input libraries. The project is hosted on SourceForge, and its source is released under a permissive license, making it suitable for both personal use and further development.