OpenTS reconstructs Command & Conquer: Tiberian Sun engine

A community of developers has released OpenTS, an open-source reconstruction of the engine for the classic real-time strategy game Command & Conquer: Tiberian Sun. Because the original source code for the 1999 title was unavailable, developers ZivDero and tomsons26 used reverse engineering to rebuild the engine function by function.

OpenTS is designed to target the behavior of the Tiberian Sun 2.03 Firestorm version. It serves as a foundation for technical modernization, bug fixes, and expanded modding capabilities. While it is not a remaster or a remake, and does not include original game assets, players must own a copy of the original game to use the new engine.

The development process utilized generative AI models, including Codex, Claude, and DeepSeek, to accelerate the final phases of the project. Developers used these tools to interpret functions and generate candidate implementations, which were then manually reviewed, compiled, and compared against the reference executable to ensure accuracy.