0 A.D. is a cross-platform real-time strategy game of ancient warfare. In short, it is a historically-based war/economy game that allows players to relive or rewrite the history of Western civilizations, focusing on the years between 500 B.C. and 500 A.D. (GPL)
Linux - Windows - macOS
Freeciv is a Free and Open Source empire-building strategy game inspired by the history of human civilization. The game commences in prehistory and your mission is to lead your tribe from the stone age to the space age. (GPL)
Linux - FreeBSD - Windows - macOS
FreeCol is a turn-based strategy game based on the old game Colonization, and similar to Civilization. (GPL)
Cross-platform
FreeOrion is a great, open-source, space-set, turn based strategy game. (GPL)
Linux - macOS - Windows
Globulation 2 is an innovative Real-Time Strategy (RTS) game which reduces micro-management by automatically assigning tasks to units. (GPL)
Linux - FreeBSD - Windows - macOS
Scorched 3D is a game based loosely (or actually quite heavily now) on the classic DOS game Scorched Earth "The Mother Of All Games". (GPL)
Linux - FreeBSD - Windows - macOS
Warzone 2100 is a real-time strategy game, originally developed by Pumpkin Studios (Archived website) and published by Eidos-Interactive. (GPL)
Linux - macOS - Windows
Widelands is a slow-paced real-time strategy free computer game under the GPL. (GPL)
Linux - FreeBSD - Windows - macOS
8 applications