Open source clone of the Age of Empires II engine
Widelands is a free, open source real-time strategy game
RTS game with the theme of Strategy by Design
Seven Kingdoms: Ancient Adversaries
0 A.D. is a free, open-source, cross-platform real-time strategy game.
Cross-platform, GPL reimplementation of the classic : Syndicate
Real-time Strategy
Open source FPS/RTS Game
An enhanced version of 7K:AA (Seven Kingdoms: Ancient Adversaries).
The classic multiplayer strategy game for use as a BBS door
A free 3d game for PC that does not limit the player. Fight,Build,Gain
Cross-platform real-time strategy game (3D)
RTSish Game Engine
A 2D Real Time Strategy space combat game.
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
Open RealStrategyGameLibrary (Engine)
WeComeInPeace is a simple RTS game that aims towards multiplayer
God game: wage war from the stone age to the future
Simple animation of a journey at light speed