strategy

0 A.D. is a real-time strategy video game under development by Wildfire Games.

A free PC Space MMORTS game set in a rich Sci-Fi world

OpenRA modernizes the classic Command & Conquer real time strategy games.

Open Source Real Time Strategy Game

OpenRA modernizes the classic Command & Conquer real time strategy games.

A 2D realtime strategy simulation with an emphasis on economy and city building.

The Battle for Wesnoth is an open source, turn-based strategy game with a high fantasy theme. It features both singleplayer and online/hotseat multiplayer combat.

Freeciv is a Free and Open Source empire-building strategy game inspired by the history of human civilization.

Planet Blupi (known as Planet Eggbert too) is a strategy and adventure game. It subtly blends action with thought-provoking challenges. Behind the quiet and gentle facade, you'll enjoy a fascinating diversion full of surprises.

Epsitec.Colobot

A sandbox-style space exploration game.

Hedgewars is a turn-based strategy, artillery, action and comedy game, featuring the antics of pink hedgehogs with attitude as they battle from the depths of hell to the depths of space.