0 A.D. is a Free open source, RTS (Real Time Strategy) MMO Game based on the years 500 B.C.
0 A.D. take the classic elements of real-time strategy gaming, where you build a civilization from scratch, recruit an army, then go massacre your enemies, and update them for the 21st century with exciting new features, a dozen fully-realized civilizations, and modern graphics powered by the custom-built open-source engine Pyrogenesis.
The years 500 B.C. through 1 B.C., when the Roman Republic saw its meteoric rise, Alexander the Great's epic empire was built and crumbled into competing kingdoms, the Celts menaced Italy and Greece from the North, and Hannibal crossed the Alps with his corps of elephants. 0 A.D. is a time that never was: A time when the civilizations of antiquity were all at the peak of their development.
Lead a civilization set in the imaginary year of 0 A.D., develop a thriving city, raise a mighty army and contend with rivals for hegemony of the world. History is yours for the taking!