0 A.D.

0 A.D. (zero eh-dee) is a free, open-source, cross-platform real-time strategy game under development by Wildfire Games. It is a historical war and economy game focusing on the years between 500 B.C. and A.D. 500 The game will be cross-platform, playable on Windows, Mac OS, and Linux. The game aims to be entirely free and open-source.