Free Strategy Games
Free Computer War Games 
A complete listing of FREE war and strategy games available for your computer. Site includes a complete listing of the best free games out there as well as some low cost games as well organized by type and by operating system. Also included are free books, board games and software as well as information about game development.
Scorched 3D
A new, improved, and 3-D version of the classic game Scorched Earth available for free! Scorched 3D has all that you loved from the previous game only with improved 3D graphics, upgrades, and online play. Play the game as a shoot em up or pay attention to your strategy and earn money for upgrades to your weapons and armor and be the last man standing.
Ta Spring Project
Spring is an open source real time strategy game based on Total Annihilation. You can find maps, unit packs, and a ton of strategy info here all for free. Interested in helping develop the game? Join the online community and be a part of making the game even better and more customizable. Licensed under GPL/Creative Commons.