- 0 A.D. (C++, GPL-2.0, beta)
- A Planet's Revenge (Python, GPL-3.0, beta, inactive since 2008)
- AI Wars (Python, MIT, beta, inactive since 2010)
- Advanced Strategic Command (C++, GPL-2.0, mature)
- Alien Assault Traders (PHP, GPL-2.0, beta, inactive since 2009)
- Ancient Beast (JavaScript, AGPL-3.0, mature)
- Antares (C++, LGPL-3.0, beta)
- AntiChess (Java, MIT, mature, inactive since 2003)
- Armies (C++, GPL-3.0, mature, inactive since 2007)
- Attal: Lords of doom (C++, GPL-2.0, mature, inactive since 2008)
- Battle for Wesnoth (C++, GPL-2.0, mature)
- Battlefield Java (Java, GPL-3.0, beta, inactive since 2011)
- Battles of Antargis (C, C++, GPL-2.0, beta, inactive since 2014)
- Birth of the Empires (C++, Custom, mature, inactive since 2016)
- BlackNova Traders (PHP, JavaScript, GPL-2.0, beta, inactive since 2012)
- Blitzkrieg (Java, GPL-3.0, beta, inactive since 2012)
- Bos Wars (C++, GPL-2.0, mature, inactive since 2013)
- Boson (C++, GPL-2.0, beta, inactive since 2006)
- Bygfoot (Java, GPL-2.0, beta)
- C-evo (Pascal, Public Domain, GPL-3.0, mature, inactive since 2013)
- Caesar IA (C++, GPL-3.0, beta)
- Call to Power 2 (C++, Custom, mature)
- CivOne (C#, CC0, beta)
- Civil (Python, GPL-2.0, beta, inactive since 2003)
- Colobot (C++, GPL-3.0, mature)
- Colonization too (C++, GPL-2.0, beta, inactive since 2004)
- Conquests (C++, GPL-2.0, mature, inactive since 2012)
- Corsix Theme Hospital (Lua, C++, MIT, mature)
- Crimson Fields (C++, GPL-2.0, mature, inactive since 2010)
- Crown and Cutlass (C++, Custom, beta, inactive since 2009)
- Dark Destiny (Java, Javascript, GPL, mature, inactive since 2016)
- Dark Oberon (C++, GPL-2.0, mature, inactive since 2009)
- Devana (PHP, zlib, beta)
- Duel Commander (C, GPL-3.0, beta, inactive since 2009)
- Dune Dynasty (C, GPL-2.0, mature, inactive since 2014)
- Dune II - The Maker (Java, MIT, beta)
- Dune Legacy (C++, GPL-2.0, mature)
- EPOH (JavaScript, MIT, beta)
- Endgame: Singularity (Python, GPL-2.0, beta)
- EternalWinterWars (Java, MIT, beta, inactive since 2014)
- Evil Cult (Haxe, JavaScript, GPL-3.0, mature)
- FAR Colony (Pascal, GPL-3.0, beta, inactive since 2014)
- First Strike (Java, MIT, mature)
- Free Mars (Java, GPL-3.0, mature)
- Free Orion (C++, Python, GPL-2.0, beta)
- Free Space Colonization (C, GPL-2.0, beta)
- Free heroes2 engine (C++, GPL-2.0, beta, inactive since 2015)
- FreeCol (Java, GPL-2.0, mature)
- FreeLords (Java, GPL-2.0, beta)
- FreeRCT (C++, GPL-2.0, beta, inactive since 2016)
- FreeRails (Java, GPL-2.0, beta)
- FreeSynd (C++, GPL-2.0, beta)
- Freeciv (C, GPL-2.0, mature)
- Freeciv WebGL (JavaScript, Java, AGPL-3.0, mature)
- Freeserf (C++, GPL-3.0, beta)
- Freestars (C++, GPL-2.0, beta, inactive since 2008)
- GalaxyNG (C, GPL-2.0, mature, inactive since 2005)
- Gigalomania (C++, GPL-2.0, mature)
- Glest (C++, GPL-2.0, mature, inactive since 2009)
- Globulation2 (C++, GPL-3.0, mature)
- Goblin Camp (C++, GPL-3.0, beta, inactive since 2012)
- Greenius' Civil War (C++, GPL-2.0, beta, inactive since 2001)
- Harris (C, Python, GPL-3.0, beta)
- Heroes of Wesnoth (C++, GPL-3.0, beta, inactive since 2010)
- Heroes of Wing Commander (Python, GPL-3.0, beta, inactive since 2014)
- Hex Game (C++, MIT, beta)
- Hexwar (Ruby, JavaScript, MIT, beta, inactive since 2012)
- Isometric Turn-Based Strategy (Python, MIT, beta)
- JQuest (Java, GPL-2.0, beta, inactive since 2006)
- JSettlers (Java, GPL-3.0, mature)
- Jagged Alliance 2 Stracciatella (C++, Custom, mature)
- Kingdoms (C++, GPL-3.0, beta, inactive since 2014)
- Knights and Merchants Remake (Pascal, AGPL-3.0, mature)
- LGeneral (C, GPL-2.0, mature)
- LordsAWar! (C++, GPL-3.0, mature)
- M.E.W.L. (C++, GPL-2.0, beta, inactive since 2015)
- Machinations (C++, GPL-2.0, beta, inactive since 2003)
- Mars, Land of No Mercy (C++, GPL-2.0, beta, inactive since 2008)
- Mechanized Assault & eXploration Reloaded (C++, C, GPL-2.0, beta, inactive since 2016)
- MegaGlest (C++, GPL-2.0, mature)
- MegaMek (Java, GPL-2.0, mature)
- Mercenary Commander (Java, 3-clause BSD, beta, inactive since 2010)
- Metal Mech (PHP, GPL-2.0, beta, inactive since 2006)
- Mpango (Java, GPL-2.0, beta, inactive since 2013)
- NetPanzer (C++, GPL-2.0, beta)
- Open Apocalypse (C++, MIT, mature)
- Open Dune (C, GPL-2.0, mature)
- Open Imperium Galactica (Java, GPL-3.0, beta)
- Open Panzer (JavaScript, GPL-2.0, mature)
- Open Soccer Star (PHP, GPL-3.0, beta)
- OpenHoMM (C++, GPL-3.0, beta, inactive since 2010)
- OpenMOO2 (Python, GPL-2.0, beta, inactive since 2011)
- OpenPop (C++, GPL-3.0, beta, inactive since 2009)
- OpenRA (C#, GPL-3.0, mature)
- OpenSoccer (PHP, GPL-3.0, beta)
- OpenWebSoccer-Sim (PHP, LGPL-3.0, mature)
- OpenXcom (C++, GPL-3.0, mature)
- Operation Citadel (C++, GPL-2.0, beta, inactive since 2000)
- Outer Space (Python, GPL-2.0, beta)
- Pax Britannica (Lua, C, MIT, mature)
- Pioneers (C, GPL-2.0, mature)
- Pizza Business (C++, GPL-2.0, mature, inactive since 2003)
- Planetary Hoppers (Java, GPL-2.0, beta, inactive since 2003)
- PokerTH (C++, AGPL-3.0, mature, inactive since 2017)
- Polis (Java, GPL-3.0, mature, inactive since 2016)
- Project Helena (Pascal, GPL-3.0, beta)
- PySol (Python, GPL-2.0, mature, inactive since 2004)
- Rails: an 18xx game system (Java, GPL-2.0, mature)
- Return to the Roots (C++, GPL-3.0, mature)
- Scorched Moon (Python, GPL-3.0, beta)
- Sengoku: Warring States of Japan (C++, Lua, MIT, beta, inactive since 2008)
- Settlers III remake (Java, MIT, beta)
- SharpKonquest (C#, GPL-2.0, mature, inactive since 2007)
- Simple-Solitaire (Java, GPL-3.0, mature)
- Skrupel - Tribute Compilation (PHP, JavaScript, GPL-2.0, mature, inactive since 2011)
- Slay (Java, GPL-3.0, beta, inactive since 2010)
- Song of Albion (C, C++, Apache-2.0, mature, inactive since 2011)
- Space Faring (Java, GPL-3.0, beta)
- Space Opera (Java, GPL-2.0, beta, inactive since 2008)
- Space Trader for Windows (C#, GPL-2.0, mature, inactive since 2009)
- Space War (Java, Apache-2.0, mature)
- SpaceTrader for Java (Java, GPL-2.0, mature, inactive since 2010)
- Spring RTS engine (C++, C, Lua, GPL-2.0, mature)
- Star Control II: The Ur-Quan Masters (C, GPL-2.0, mature, inactive since 2011)
- Star Ruler 2 (C, C++, MIT, mature)
- Stareater (C#, GPL-3.0, beta)
- Stars! Nova (C#, GPL-2.0, beta)
- Supremacy (C#, Ms-RL, beta, inactive since 2014)
- T-Bots (C, GPL-2.0, beta, inactive since 2004)
- TVTower (BlitzMax, Lua, Custom, mature)
- Tanks of Freedom (GDScript, MIT, mature)
- The Epic of Heroes (C++, GPL-3.0, beta, inactive since 2015)
- Thousand Parsec (C++, Python, GPL-2.0, beta, inactive since 2012)
- TripleA (Java, GPL-2.0, mature)
- Turious (C, GPL-3.0, beta, inactive since 2014)
- Turn of War (Java, GPL-3.0, beta)
- UFO2000 (C++, GPL-2.0, mature, inactive since 2012)
- Ufo: Alien Invasion (C, C++, GPL-2.0, mature)
- Unknown Horizons (Python, GPL-2.0, beta)
- VCMI Project (C++, GPL-2.0, mature)
- WAtomic (Pascal, GPL-2.0, mature, inactive since 2005)
- War Of Kingdom (C, C++, GPL-2.0, beta)
- Wargamer (C++, GPL-2.0, mature, inactive since 2003)
- Wargus (C++, Lua, GPL-2.0, mature)
- Warzone 2100 (C++, GPL-2.0, mature)
- Widelands (C++, Lua, GPL-2.0, mature)
- Wizards Magic (Python, GPL-2.0, mature, inactive since 2012)
- Wolfpack Empire (C, GPL-3.0, mature)
- World of Heroes (Python, 3-clause BSD, beta, inactive since 2009)
- Wyrmsun (Lua, C++, GPL-2.0, mature)
- X-Force: Fight For Destiny (Pascal, GPL-2.0, beta, inactive since 2011)
- XArchon (C, C++, GPL-2.0, beta, inactive since 2003)
- XSera (C, Lua, MIT, beta, inactive since 2010)
- Xconq (C++, GPL-2.0, mature, inactive since 2005)
- Xenowar (C, C++, GPL-3.0, mature, inactive since 2014)
- Zero Ballistics (C++, MIT, mature, inactive since 2013)
- Zero-K (Lua, GPL-2.0, mature)
- Zetawar (Clojure, MIT, mature)
- Zone of Control (Rust, Apache-2.0, beta, inactive since 2017)