0 A.D.
A free, open-source real-time strategy game about ancient civilizations, with single-player, multiplayer, and modding support.
0 A.D. is a free, open-source, cross-platform real-time strategy game of ancient warfare developed by Wildfire Games. Players build settlements, gather resources, research technologies, train armies, and command historical civilizations in single-player and multiplayer matches.
The project includes the Pyrogenesis game engine and the Atlas map editor, and supports community-created modifications. Official builds are available for Windows, Linux, and macOS. The source code and much of the game data are released under GPL version 2 or later, while some artwork and third-party components use separate licenses.
0 A.D. is a free alternative to the Age of Empires series for players who want a historical RTS that can be downloaded, played, and modified without a commercial license or subscription.