- 0 A.D. (C, C++, JavaScript, GPL-2.0, beta)
- 1oom (C, GPL-2.0, mature)
- 2Moons Browsergame Engine (PHP, JavaScript, MIT, mature)
- A Planet's Revenge (Python, GPL-3.0, beta, inactive since 2008)
- Advanced Strategic Command (C++, GPL-2.0, mature)
- AI Wars (Python, MIT, beta, inactive since 2010)
- Alien Assault Traders (PHP, GPL-2.0, beta, inactive since 2009)
- Allure of the Stars (Haskell, AGPL-3.0, beta)
- Ancient Beast (JavaScript, AGPL-3.0, mature)
- android-chess (Java, C++, MIT, mature)
- Annex: Conquer the World (Lua, GPL-3.0, mature, inactive since 2014)
- Antares (C++, LGPL-3.0, beta)
- AntiChess (Java, MIT, beta, inactive since 2003)
- Anuto (Java, GPL-2.0, mature)
- Armies (C++, GPL-3.0, mature, inactive since 2007)
- Armor Alley (JavaScript, CC-BY-NC-3.0, beta)
- Arrakis (Basic, Custom, mature, inactive since 2000)
- Attal: Lords of doom (C++, GPL-2.0, mature, inactive since 2008)
- Aussenposten (JavaScript, MIT, beta, inactive since 2015)
- Balder2D (C++, GPL-2.0, beta, inactive since 2009)
- Battle City (C, C++, Pascal, GPL-3.0, mature, inactive since 2013)
- 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)
- BitRiot (C++, Apache-2.0, beta, inactive since 2017)
- BlackNova Traders (PHP, JavaScript, GPL-2.0, beta, inactive since 2012)
- Blitzkrieg (Java, GPL-3.0, beta, inactive since 2012)
- Block Puzzle Stone Wars (Java, MIT, mature)
- boardgame.io (JavaScript, TypeScript, MIT, beta)
- Bos Wars (C++, GPL-2.0, mature, inactive since 2013)
- Boson (C++, C, GPL-2.0, beta, inactive since 2006)
- Brutal Chess (C++, GPL-2.0, beta, inactive since 2007)
- Bygfoot (Java, GPL-2.0, beta)
- C-evo (Pascal, Public domain, GPL-3.0, mature, inactive since 2013)
- c64-nuclearreaction (C, Assembly, GPL-3.0, mature, inactive since 2014)
- CaesarIA (C++, JavaScript, C, GPL-3.0, beta)
- Castle-Combat (Python, GPL-2.0, beta, inactive since 2006)
- Catan Dice Game (Java, GPL-3.0, mature)
- cc94 (C++, Python, AGPL-3.0, beta)
- CCCP (C++, AGPL-3.0, beta)
- chainreaction (Java, LGPL-3.0, mature, inactive since 2017)
- Chaos Esque Anthology (?, ?, mature)
- Chariot (Rust, MIT, beta, inactive since 218)
- Chess3D (JavaScript, Python, GPL-3.0, mature, inactive since 2016)
- Civ2-clone (C#, GPL-3.0, beta)
- Civil (Python, GPL-2.0, beta, inactive since 2003)
- Civilization: Call To Power 2 Source Project (C, C++, Custom, mature)
- CivOne (C#, CC0, beta)
- Colditz Escape (C, GPL-3.0, mature)
- Colobot: Gold Edition (C++, GPL-3.0, mature)
- Colonization too (C++, GPL-2.0, beta, inactive since 2004)
- Command Series Engine (Go, GPL-2.0, mature)
- Conquest (C++, MIT, mature)
- Conquests (C++, GPL-2.0, mature, inactive since 2012)
- CorsixTH (Lua, C++, MIT, mature)
- Crimson Fields (C++, C, GPL-2.0, mature, inactive since 2010)
- Critterding (C++, GPL-2.0, beta, inactive since 2013)
- Crown and Cutlass (C++, C, Custom, beta, inactive since 2009)
- Curse of War (C, C++, GPL-3.0, mature, inactive since 2014)
- Dark Destiny (Java, JavaScript, ?, mature, inactive since 2016)
- Dark Oberon (C++, C, Objective-C, GPL-2.0, mature, inactive since 2009)
- Defendo (GDScript, PHP, GPL-3.0, mature, inactive since 2018)
- Devana (PHP, zlib, beta)
- Domination (Java, GPL-3.0, mature)
- DreamChess (C, GPL-3.0, beta)
- DroidZebra (C, Java, GPL-3.0, mature, inactive since 2015)
- Duel Commander (C, GPL-3.0, beta, inactive since 2009)
- Dune Dynasty (C, C++, GPL-2.0, mature, inactive since 2014)
- Dune II - The Maker (Java, MIT, beta)
- Dune Legacy (C++, GPL-2.0, mature)
- DwarfCorp (C#, MIT, mature)
- Eboard (C++, GPL-2.0, mature)
- Enchanted Fortress (Java, LGPL-3.0, mature)
- Endgame: Singularity (Python, GPL-2.0, beta)
- EPOH (JavaScript, MIT, 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, inactive since 2018)
- Fish Rings for Android (Java, GPL-3.0, mature, inactive since 2015)
- fonline (C, C++, C#, GPL-3.0, beta)
- Forge (Java, GPL-3.0, mature)
- Foursies (Elm, JavaScript, GPL-3.0, mature, inactive since 2016)
- Free Allegiance (C++, MIT, mature)
- Free Heroes 2 (C++, GPL-2.0, beta, inactive since 2015)
- Free Mars (Java, GPL-3.0, mature)
- Free Space Colonization (C, GPL-2.0, beta, inactive since 2017)
- Free Tennis (OCaml, GPL-2.0, beta, inactive since 2005)
- freeaoe (C++, GPL-3.0, beta)
- Freebloks 3D for Android (Kotlin, C++, GPL-2.0, mature)
- Freeciv Alpha Centauri project (C, GPL-2.0, beta, inactive since 2003)
- Freeciv-web (JavaScript, Java, Python, AGPL-3.0, mature)
- Freeciv (C, GPL-2.0, mature)
- FreeCol (Java, GPL-2.0, mature)
- FrEee (C#, CC-BY-NC-SA-2.0, beta)
- FreeLords (Java, GPL-2.0, beta, inactive since 2017)
- FreeOrion (C++, Python, GPL-2.0, beta)
- FreeRails (Java, C++, GPL-2.0, beta, inactive since 2008)
- FreeRCT (C++, GPL-2.0, beta, inactive since 2016)
- Freeserf.net (C#, GPL-3.0, mature)
- Freeserf (C, C++, GPL-3.0, mature)
- FreeSiege (C++, GPL-3.0, beta)
- Freestars (C++, GPL-2.0, beta, inactive since 2008)
- FreeSynd (C++, GPL-2.0, beta, inactive since 2017)
- Freya Game Engine (Java, LGPL-2.1, beta, inactive since 2002)
- GalaxyNG (C, PHP, Script, GPL-2.0, mature, inactive since 2005)
- Gigalomania (C++, GPL-2.0, mature)
- Gilbert and the doors (C, GPL-3.0, mature, inactive since 2018)
- Glest (C++, Script, GPL-2.0, mature, inactive since 2009)
- Globulation 2 (C++, GPL-3.0, mature)
- glParchis (Python, GPL-3.0, mature)
- Gnome Chess (Vala, GPL-3.0, mature)
- Gnome Hearts (Python, GPL-2.0, mature, inactive since 2015)
- GNU Chess (C++, GPL-3.0, mature, inactive since 2017)
- GNU Go (C, GPL-3.0, mature, inactive since 2011)
- GNU Shogi (C, GPL-3.0, mature, inactive since 2018)
- Goblin Camp (C++, Python, GPL-3.0, beta, inactive since 2012)
- Greenius' Civil War (C++, C, GPL-2.0, beta, inactive since 2001)
- Harris (C, Python, GPL-3.0, beta)
- Hase (C, GPL-3.0, beta)
- Heroes of Civilizations (C++, C#, GPL-2.0, 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)
- HHexen (C, GPL-2.0, mature, inactive since 2013)
- Hnefatafl (C, ISC, beta, inactive since 2014)
- Infon Battle Arena (C, Lua, GPL-2.0, beta, inactive since 2012)
- Isolmoa (JavaScript, Java, GPL-3.0, mature, inactive since 2014)
- Isometric Turn-Based Strategy (Python, MIT, beta)
- Isometric-Minesweeper (Python, MIT, beta)
- Ithaka Board Game (Java, GPL-3.0, mature)
- Jagged Alliance 2 Stracciatella (C, C++, Custom, mature)
- JQuest (Java, GPL-2.0, beta, inactive since 2006)
- JSettlers (Java, GPL-3.0, mature)
- KaM Remake (Pascal, AGPL-3.0, mature)
- Kingdoms (C++, GPL-3.0, beta, inactive since 2014)
- KittenMaxit (Java, MIT, beta)
- LGeneral (C, GPL-2.0, mature, inactive since 2017)
- Liberal Crime Squad (C++, GPL-2.0, mature, inactive since 2012)
- Liberation Circuit (C, GPL-3.0, mature)
- Liquid Wars (C++, Java, GPL-3.0, mature, inactive since 2014)
- LMarbles (C, GPL-2.0, beta)
- Lords of the Fey (JavaScript, AGPL-3.0, beta, inactive since 2018)
- LordsAWar! (C++, GPL-3.0, mature)
- M.E.W.L. (C++, GPL-2.0, beta, inactive since 2015)
- Machinations (C++, C, GPL-2.0, beta, inactive since 2003)
- Magic Gardeners Tournament (Python, GPL-2.0, beta, inactive since 2007)
- Mah-Jong (C, GPL-2.0, mature)
- Mars, Land of No Mercy (C++, GPL-2.0, beta, inactive since 2008)
- Maxit (C++, 3-clause BSD, mature, inactive since 2014)
- mc2 (C++, GPL-3.0, beta)
- Mechanized Assault & eXploration Reloaded (C++, C, GPL-2.0, beta)
- MegaGlest (C, C++, GPL-3.0, mature)
- MegaMek (Java, GPL-2.0, mature)
- MekWars (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)
- Mines (Vala, GPL-3.0, mature)
- Minos (Java, GPL-3.0, mature)
- Mpango (Java, JavaScript, GPL-2.0, beta, inactive since 2013)
- NetPanzer (C++, GPL-2.0, beta)
- NStars! (C#, ?, beta, inactive since 2004)
- Omega (JavaScript, Ruby, AGPL-3.0, beta)
- Online Chess Club (PHP, JavaScript, GPL-2.0, mature)
- Open Apocalypse (C++, MIT, beta)
- Open Imperium Galactica (Java, LGPL-3.0, mature)
- Open Panzer (JavaScript, GPL-2.0, mature)
- Open Quartz (C, GPL-2.0, beta, inactive since 2004)
- Open Soccer Star (PHP, GPL-3.0, beta)
- Open Yahtzee (C++, GPL-2.0, mature, inactive since 2016)
- openage (C++, Python, GPL-3.0, beta)
- OpenDominion (PHP, AGPL-3.0, beta)
- openDOW (C, GPL-3.0, beta)
- OpenDUNE (C, GPL-2.0, mature)
- OpenDungeons (C++, GPL-3.0, beta)
- OpenHoMM (C++, GPL-3.0, beta, inactive since 2010)
- OpenHoW (C, C++, GPL-3.0, beta)
- OpenHV (C#, Lua, GPL-3.0, beta)
- OpenMoM (C, C++, GPL-3.0, beta)
- OpenMOO2 (Python, GPL-2.0, beta, inactive since 2011)
- OpenRA (C#, GPL-3.0, mature)
- OpenRTS (Python, GPL-2.0, beta, inactive since 2006)
- OpenSA (C#, Lua, GPL-3.0, mature)
- OpenSAGE (C#, LGPL-3.0, beta)
- 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)
- Orbium (JavaScript, GPL-2.0, mature, inactive since 2018)
- orona (CoffeeScript, GPL-2.0, beta, inactive since 2012)
- Outer Space (Python, GPL-2.0, beta)
- Pachi (C, Python, GPL-2.0, mature)
- Pasang Emas (Vala, GPL-3.0, mature)
- Pax Britannica (Lua, C, MIT, mature)
- Permafrost Engine (C, Python, GPL-3.0, mature)
- Pioneers (C, GPL-2.0, mature)
- PipePanic (Java, JavaScript, MIT, mature, inactive since 2016)
- Pizza Business (C++, GPL-2.0, mature, inactive since 2003)
- Planet Conquest (Java, GPL-3.0, mature, inactive since 2017)
- 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)
- Prescription Wars (ColdFusion, JavaScript, GPL-3.0, mature, inactive since 2016)
- Project Helena (Pascal, GPL-3.0, beta, inactive since 2018)
- PySol (Python, GPL-2.0, mature, inactive since 2004)
- Qonk (C++, GPL-2.0, beta, inactive since 2008)
- Quatter (C++, GPL-2.0, mature, inactive since 2018)
- Race Into Space (C, C++, GPL-2.0, mature)
- Rails: an 18xx game system (Java, GPL-2.0, mature)
- Rescue! Max (Java, GPL-3.0, beta, inactive since 2013)
- Return to the Roots (C++, GPL-3.0, mature)
- Scorched Moon (Python, GPL-3.0, beta)
- Scorched3D (C++, GPL-2.0, mature, inactive since 2014)
- Scrabble3D (Pascal, GPL-3.0, mature, inactive since 2015)
- Scrap (C, C++, GPL-2.0, mature, inactive since 2017)
- Search for the Red Herring (Python, GPL-2.0, mature, inactive since 2006)
- Sengoku: Warring States of Japan (C++, Lua, MIT, beta, inactive since 2008)
- Settlers III remake (Java, MIT, beta)
- Seven Kingdoms: Ancient Adversaries (C++, GPL-2.0, mature)
- 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)
- Slingshot (Python, GPL-2.0, beta, inactive since 2007)
- Snelps (Ruby, LGPL-2.1, beta, inactive since 2012)
- Snowballz (Python, GPL-2.0, beta, inactive since 2007)
- Song of Albion (C, C++, Apache-2.0, mature, inactive since 2011)
- Space Faring (Java, GPL-3.0, beta)
- Space Harrier Clone (C, C++, MIT, beta, inactive since 2018)
- Space Nerds In Space (C, Lua, GPL-2.0, beta)
- Space Opera (Java, GPL-2.0, beta, inactive since 2008)
- Space Trader for Android (Java, GPL-3.0, mature, inactive since 2016)
- 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)
- SpaceZero (C, GPL-3.0, beta)
- Spring: 1944 (Lua, GPL-2.0, CC-BY-NC-3.0, mature)
- Spring (C++, C, Lua, GPL-2.0, mature)
- Star Ruler 2 (C, C++, MIT, mature)
- Stareater (C#, GPL-3.0, beta)
- Stars! Nova (C#, GPL-2.0, beta)
- Stockfish (C++, GPL-3.0, mature)
- Stratagus (C++, GPL-2.0, mature)
- Supremacy (C#, MS-RL, beta, inactive since 2014)
- Syndicate Wars Port (C, GPL-3.0, beta, inactive since 2010)
- T-Bots (C, C++, GPL-2.0, beta, inactive since 2004)
- Tactics Squad (C++, GPL-2.0, beta, inactive since 2007)
- Tanks of Freedom (GDScript, MIT, mature)
- Tenes Empanadas Graciela (C, JavaScript, Perl, C++, GPL-2.0, beta, inactive since 2015)
- Tennix! (C, C++, GPL-2.0, mature)
- The Battle for Wesnoth (C, C++, Java, Python, Lua, GPL-2.0, mature)
- The Epic of Heroes (C++, GPL-3.0, beta, inactive since 2015)
- The Knights of Alentejo (Java, C++, 2-clause BSD, beta)
- The Ur-Quan Masters (C, GPL-2.0, mature, inactive since 2011)
- thiefcatcher (C++, GPL-3.0, beta)
- Thousand Parsec (C++, Python, GPL-2.0, beta, inactive since 2012)
- Thrive (C++, AngelScript, JavaScript, C#, GPL-3.0, beta)
- Thunder&Lightning (C, C++, Io, GPL-2.0, beta, inactive since 2015)
- Thyme (C, C++, GPL-2.0, beta)
- Total Annihilation 3D (C++, C, Lua, GPL-2.0, beta, inactive since 2017)
- TowerJumper (C++, GDScript, GPL-3.0, mature)
- TripleA (Java, GPL-2.0, mature)
- Turious (C, GPL-3.0, beta, inactive since 2014)
- Turn of War (Java, GPL-3.0, beta, inactive since 2014)
- TVTower (BlitzMax, Lua, Custom, mature)
- UFO2000 (C, C++, Lua, GPL-2.0, mature, inactive since 2012)
- UFO: Alien Invasion (C, C++, GPL-2.0, mature)
- UnCiv (Kotlin, MPL-2.0, beta)
- Unknown Horizons (Python, GDScript, GPL-2.0, beta)
- Vanilla-Conquer (C, C++, Assembly, GPL-3.0, mature)
- VCMI (C++, GPL-2.0, mature)
- VMS Empire (C, GPL-2.0, mature, inactive since 2014)
- Walic (Kotlin, Apache-2.0, mature)
- War Of Kingdom (C, C++, GPL-2.0, beta)
- War1 (C, zlib, beta)
- warcraft-remake (Java, GPL-2.0, beta)
- Wargamer (C++, GPL-2.0, mature, inactive since 2003)
- Wargus (C++, Lua, C, GPL-2.0, mature)
- Warzone 2100 (C++, GPL-2.0, mature)
- WAtomic (Pascal, GPL-2.0, mature, inactive since 2005)
- WebChess (PHP, GPL-3.0, mature, inactive since 2010)
- Widelands (C, C++, Lua, Python, GPL-2.0, mature)
- Wizards Magic (Python, GPL-2.0, mature, inactive since 2012)
- wkbre (C++, C, GPL-3.0, beta)
- 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)
- Xconq (C++, C, Script, GPL-2.0, mature, inactive since 2005)
- Xenowar (C, C++, GPL-3.0, mature, inactive since 2014)
- XMage (Java, MIT, mature)
- XSera (C, Lua, MIT, beta, inactive since 2010)
- XSkat (Java, Custom, mature)
- Zed Online (C++, ?, mature)
- Zero Ballistics (C++, MIT, mature, inactive since 2013)
- Zero-K (Lua, GPL-2.0, mature)
- Zetawar (Clojure, MIT, mature)
- Zod Engine (C++, ?, mature, inactive since 2018)
- Zone of Control (Rust, Apache-2.0, beta, inactive since 2017)