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
Command and Conquer: Red Alert original source code
0 A.D. is a free, open-source, cross-platform real-time strategy game.
Cross-platform, GPL reimplementation of the classic : Syndicate
Open source FPS/RTS Game
Real-time Strategy
An enhanced version of 7K:AA (Seven Kingdoms: Ancient Adversaries).
A free 3d game for PC that does not limit the player. Fight,Build,Gain
The classic multiplayer strategy game for use as a BBS door
War of seventh kings
RTSish Game Engine
Cross-platform real-time strategy game (3D)
A 2D Real Time Strategy space combat game.
Lines a game written in Python two players through internet
Spring is a free RTS engine developed for Windows, Linux and Mac OS X.
Total War Savegame Editor / Parser
Open RealStrategyGameLibrary (Engine)
WeComeInPeace is a simple RTS game that aims towards multiplayer