0 A.D. - 0 A. D. is a free, open-source, historical Real Time Strategy (RTS) game currently under development by Wildfire Games, a global group of volunteer game developers. Download 0 A. D.
Age of Empires - Age of Empires is the critically acclaimed, award winning Real Time Strategy (RTS) game with a legacy spanning over 20 years and nearly a dozen titles in the franchise.
openage - Free Age of Empires II clone
Age of Mythology - Age of Mythology. The game that transports players to a time when heroes did battle with monsters of legend and the gods intervened in the affairs of mortals. Use mythological creatures like Minotaurs and Cyclopes to bolster your armies' strength.
Stronghold - Stronghold Crusader is a RTS game from the series from Stronghold.
OpenRA - What if Albert Einstein changed history? What if the Andromeda Strain were a miracle mineral?