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.
TripleA - TripleA is a free (under GPL) turn based strategy game based on Axis & Allies board game.
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.
Warlight - Warzone is a customizable Risk-like strategy game where you compete with your friends to conquer the world.
Stronghold - Stronghold Crusader is a RTS game from the series from Stronghold.
Domination - Domination is a game that is a bit like the well known board game of Risk.