[comment]: # (autogenerated content, do not edit)
# All

- **[0 A.D.](0_ad.md)** (C, C++, GPL-2.0, beta)
- **[1oom](1oom.md)** (C, GPL-2.0, mature)
- **[2048](2048.md)** (JavaScript, MIT, mature)
- **[3d.city](3dcity.md)** (JavaScript, GPL-3.0, mature, inactive since 2016)
- **[4D-TRIS](4d-tris.md)** (C, GPL-2.0, mature, inactive since 2012)
- **[A Planet's Revenge](a_planets_revenge.md)** (Python, GPL-3.0, beta, inactive since 2008)
- **[Abuse](abuse.md)** (C++, Lisp, Public domain, GPL-2.0, WTFPL, mature, inactive since 2011)
- **[Achtung, die Kurve!](achtung_die_kurve.md)** (JavaScript, AGPL-3.0, mature)
- **[AdaVenture](adaventure.md)** (Ada, GPL-3.0, mature)
- **[Advanced Strategic Command](advanced_strategic_command.md)** (C++, GPL-2.0, mature)
- **[Afternoon Stalker](afternoon_stalker.md)** (C++, GPL-2.0, mature, inactive since 2012)
- **[AI Wars](ai_wars.md)** (Python, MIT, beta, inactive since 2010)
- **[Ajax3d](ajax3d.md)** (JavaScript, GPL-2.0, beta, inactive since 2007)
- **[Aklabeth](aklabeth.md)** (C, GPL-2.0, mature, inactive since 2004)
- **[Aleph One](aleph_one.md)** (C++, Lua, GPL-3.0, mature, inactive since 2015)
- **[Alien Assault Traders](alien_assault_traders.md)** (PHP, GPL-2.0, beta, inactive since 2009)
- **[alive](alive.md)** (C++, MIT, beta, inactive since 2017)
- **[Allegro](allegro.md)** (C, zlib, mature)
- **[Ancient Beast](ancient_beast.md)** (JavaScript, AGPL-3.0, mature)
- **[Andor's Trail](andors_trail.md)** (Java, GPL-2.0, beta)
- **[Angband](angband.md)** (C, GPL-2.0, mature)
- **[Annchienta](annchienta.md)** (C++, GPL-3.0, mature, inactive since 2009)
- **[Antares](antares.md)** (C++, LGPL-3.0, beta)
- **[AntiChess](antichess.md)** (Java, MIT, mature, inactive since 2003)
- **[aquastax](aquastax.md)** (JavaScript, MIT, beta)
- **[Arashi-JS](arashi-js.md)** (JavaScript, GPL-2.0, beta, inactive since 2010)
- **[Ardentryst](ardentryst.md)** (Python, GPL-3.0, mature, inactive since 2009)
- **[Argentum Online](argentum_online.md)** (Visual Basic, GPL-2.0, beta, inactive since 2014)
- **[Arianne / Marauroa](arianne_marauroa.md)** (Java, GPL-2.0, mature)
- **[Armagetron Advanced](armagetron_advanced.md)** (C++, GPL-2.0, mature)
- **[Armies](armies.md)** (C++, GPL-3.0, mature, inactive since 2007)
- **[Armor Alley](armor_alley.md)** (JavaScript, CC-BY-NC, beta)
- **[Artillery Duel Reloaded](artillery_duel_reloaded.md)** (Python, GPL-3.0, beta, inactive since 2012)
- **[Arx Libertatis](arx_libertatis.md)** (C++, GPL-3.0, mature)
- **[asdf](asdf.md)** (JavaScript, MIT, mature)
- **[AstroMenace](astromenace.md)** (C++, C, GPL-3.0, mature)
- **[ativayeban](ativayeban.md)** (C, C++, GPL-2.0, mature, inactive since 2015)
- **[Atlantis](atlantis.md)** (C++, GPL-2.0, mature, inactive since 2016)
- **[Atomic Tanks](atomic_tanks.md)** (C++, GPL-2.0, mature, inactive since 2016)
- **[Atomiks](atomiks.md)** (C, GPL-3.0, mature, inactive since 2015)
- **[Atomix](atomix.md)** (C, GPL-2.0, mature)
- **[Atrinik](atrinik.md)** (C, Python, GPL-2.0, mature, inactive since 2016)
- **[Attal: Lords of doom](attal_lords_of_doom.md)** (C++, GPL-2.0, mature, inactive since 2008)
- **[AutoREALM](autorealm.md)** (C++, GPL-3.0, mature)
- **[Avanor](avanor.md)** (C++, Lua, GPL-2.0, beta, inactive since 2008)
- **[Ball And Wall](ball_and_wall.md)** (JavaScript, MIT, mature, inactive since 2015)
- **[Ballerburg SDL](ballerburg_sdl.md)** (C, GPL3, mature)
- **[Barony](barony.md)** (C++, GPL-3.0, mature)
- **[Batrachians](batrachians.md)** (C++, GPL-2.0, beta, inactive since 2012)
- **[Battle City](battle_city.md)** (C, C++, Pascal, GPL-3.0, mature, inactive since 2013)
- **[Battle Tanks](battle_tanks.md)** (C++, GPL-2.0, mature, inactive since 2009)
- **[Battlefield Java](battlefield_java.md)** (Java, GPL-3.0, beta, inactive since 2011)
- **[Battleround](battleround.md)** (Java, Apache-2.0, beta, inactive since 2015)
- **[Battles of Antargis](battles_of_antargis.md)** (C, C++, GPL-2.0, beta, inactive since 2014)
- **[Betrayer's Moon Tactics](betrayers_moon_tactics.md)** (JavaScript, GPL-2.0, beta, inactive since 2006)
- **[Biniax](biniax.md)** (C, zlib, mature, inactive since 2012)
- **[Birth of the Empires](birth_of_the_empires.md)** (C++, Custom, mature, inactive since 2016)
- **[BitRiot](bitriot.md)** (C++, Apache-2.0, beta, inactive since 2017)
- **[BlackNova Traders](blacknova_traders.md)** (PHP, JavaScript, GPL-2.0, beta, inactive since 2012)
- **[BlakedAwesomenaughts](blakedawesomenaughts.md)** (JavaScript, PHP, MIT, beta, inactive since 2015)
- **[Blender game engine](blender_game_engine.md)** (C++, GPL-2.0, mature)
- **[Blitzkrieg](blitzkrieg.md)** (Java, GPL-3.0, beta, inactive since 2012)
- **[Blobby Volley 2](blobby_volley_2.md)** (C++, GPL-2.0, mature, inactive since 2017)
- **[Blobwars: Metal Blob Solid](blobwars_metal_blob_solid.md)** (C++, GPL-2.0, mature)
- **[Block Attack - Rise of the Blocks](block_attack-rise_of_the_blocks.md)** (C++, GPL-2.0, mature)
- **[BlockOut II](blockout_ii.md)** (C++, GPL-2.0, mature, inactive since 2014)
- **[Bombermaaan](bombermaaan.md)** (C++, GPL-3.0, mature, inactive since 2010)
- **[Bombic2](bombic2.md)** (C++, GPL-2.0, beta, inactive since 2010)
- **[Bombic](bombic.md)** (C++, GPL-2.0, beta, inactive since 2005)
- **[Bombman](bombman.md)** (Python, CC0, mature)
- **[BOOM: Remake](boom_remake.md)** (C++, Custom, mature)
- **[Boost (C++ Libraries)](boost_c_libraries.md)** (C++, Boost-1.0, mature)
- **[Bos Wars](bos_wars.md)** (C++, GPL-2.0, mature, inactive since 2013)
- **[Boson](boson.md)** (C++, GPL-2.0, beta, inactive since 2006)
- **[Boulder Dash](boulder_dash.md)** (Java, MIT, mature, inactive since 2015)
- **[Brain Workshop](brain_workshop.md)** (Python, GPL-2.0, mature, inactive since 2011)
- **[bratwurst](bratwurst.md)** (Lisp, GPL-2.0, mature, inactive since 2009)
- **[Breakout-VR](breakout-vr.md)** (C#, MIT, beta, inactive since 2017)
- **[Bridge Command](bridge_command.md)** (C++, GPL-2.0, mature)
- **[BRIQUOLO](briquolo.md)** (C++, GPL-3.0, mature, inactive since 2008)
- **[BrowserQuest](browserquest.md)** (JavaScript, MPL-2.0, mature)
- **[Brutal Chess](brutal_chess.md)** (C++, GPL-2.0, beta, inactive since 2007)
- **[BStone](bstone.md)** (C++, GPL-2.0, mature)
- **[Bt Builder](bt_builder.md)** (C, C++, GPL-3.0, beta)
- **[BurgerSpace](burgerspace.md)** (C++, GPL-2.0, mature, inactive since 2013)
- **[Bygfoot](bygfoot.md)** (Java, GPL-2.0, beta)
- **[BZFlag](bzflag.md)** (C++, LGPL-2.1, MPL-2.0, mature)
- **[C-Dogs SDL](c-dogs_sdl.md)** (C, GPL-2.0, mature)
- **[C-evo](c-evo.md)** (Pascal, Public domain, GPL-3.0, mature, inactive since 2013)
- **[c64-nuclearreaction](c64-nuclearreaction.md)** (C, Assembly, GPL-3.0, mature, inactive since 2014)
- **[Cabbages and Kings](cabbages_and_kings.md)** (Python, MIT, mature)
- **[Cadaver](cadaver.md)** (C++, GPL-2.0, beta, inactive since 2009)
- **[CaesarIA](caesaria.md)** (C++, JavaScript, GPL-3.0, beta)
- **[Candy Box 2](candy_box_2.md)** (TypeScript, JavaScript, GPL-3.0, mature, inactive since 2013)
- **[Cannonball](cannonball.md)** (C++, MAME, beta)
- **[Cart Life](cart_life.md)** (AGS Script, Custom, mature, inactive since 2014)
- **[Castle Game Engine](castle_game_engine.md)** (Pascal, LGPL-2.0, mature)
- **[Castle of the Winds in Elm](castle_of_the_winds_in_elm.md)** (Elm, JavaScript, ???, beta)
- **[Castle of the Winds](castle_of_the_winds.md)** (JavaScript, MIT, beta, inactive since 2016)
- **[Castle-Combat](castle-combat.md)** (Python, GPL-2.0, beta, inactive since 2006)
- **[Cat Mother Dead Justice](cat_mother_dead_justice.md)** (C++, 3-clause BSD, GPL-2.0, beta, inactive since 2003)
- **[Cataclysm: Dark Days Ahead](cataclysm_dark_days_ahead.md)** (C++, CC-BY-SA-3.0, mature)
- **[Cataclysm](cataclysm.md)** (C++, CC-BY-SA-3, beta, inactive since 2012)
- **[CatacombSDL](catacombsdl.md)** (C, GPL-2.0, mature, inactive since 2014)
- **[Catch Challenger](catch_challenger.md)** (C++, GPL-3.0, mature)
- **[CaveExpress](caveexpress.md)** (C, GPL-3.0, mature)
- **[CavePacker](cavepacker.md)** (JavaScript, C, C++, Lua, GPL-3.0, mature)
- **[cc94](cc94.md)** (C++, Python, AGPL-3.0, beta)
- **[CCCP](cccp.md)** (C++, AGPL-3.0, beta)
- **[Celestron](celestron.md)** (Python, GPL-3.0, beta, inactive since 2012)
- **[chainreaction](chainreaction.md)** (Java, LGPL-3.0, mature, inactive since 2017)
- **[Childsplay](childsplay.md)** (Python, GPL-3.0, mature)
- **[Chocolate Doom](chocolate_doom.md)** (C, GPL-2.0, mature)
- **[Chocolate Duke3D](chocolate_duke3d.md)** (C, GPL-2.0, Custom, beta)
- **[Choria](choria.md)** (C++, C, Lua, GPL-3.0, mature)
- **[Chromium B.S.U.](chromium_bsu.md)** (C++, Artistic License, mature)
- **[Chronoshift](chronoshift.md)** (C++, GPL-2.0, beta)
- **[Circus Linux!](circus_linux.md)** (C, GPL-2.0, mature, inactive since 2000)
- **[Civil](civil.md)** (Python, GPL-2.0, beta, inactive since 2003)
- **[Civilization: Call To Power 2 Source Project](civilization_call_to_power_2_source_project.md)** (C, C++, Custom, mature)
- **[CivOne](civone.md)** (C#, CC0, beta)
- **[Classic Blades of Exile](classic_blades_of_exile.md)** (C++, GPL-2.0, mature)
- **[Clonepoint](clonepoint.md)** (C++, GPL-3.0, beta)
- **[Clumsy Bird](clumsy_bird.md)** (JavaScript, MIT, mature, inactive since 2017)
- **[coab](coab.md)** (C#, ???, mature)
- **[COCOS2D-X](cocos2d-x.md)** (C++, MIT, mature)
- **[Colditz Escape](colditz_escape.md)** (C, GPL-3.0, mature)
- **[Colobot: Gold Edition](colobot_gold_edition.md)** (C++, GPL-3.0, mature)
- **[Colonization too](colonization_too.md)** (C++, GPL-2.0, beta, inactive since 2004)
- **[Colossal Cave Adventure](colossal_cave_adventure.md)** (Python, Apache-2.0, mature)
- **[Commander Genius](commander_genius.md)** (C, C++, GPL-2.0, mature)
- **[CommandoJS](commandojs.md)** (JavaScript, CoffeeScript, MIT, beta, inactive since 2012)
- **[Conquests](conquests.md)** (C++, GPL-2.0, mature, inactive since 2012)
- **[Core War](core_war.md)** (C, Java, GPL-2.0, 2-clause BSD, mature)
- **[CorsixTH](corsixth.md)** (Lua, C++, MIT, mature)
- **[Cosmosmash](cosmosmash.md)** (C++, GPL-2.0, mature, inactive since 2013)
- **[Crack Attack!](crack_attack.md)** (C++, GPL-2.0, mature, inactive since 2005)
- **[Craft](craft.md)** (C, Python, MIT, mature, inactive since 2017)
- **[CrappyBird](crappybird.md)** (JavaScript, MIT, mature, inactive since 2017)
- **[Crimson Fields](crimson_fields.md)** (C++, GPL-2.0, mature, inactive since 2010)
- **[Crossfire](crossfire.md)** (C, Java, GPL-2.0, mature)
- **[Crown and Cutlass](crown_and_cutlass.md)** (C++, Custom, beta, inactive since 2009)
- **[Crypto++](crypto.md)** (C++, Boost-1.0, mature)
- **[CrystalQuest](crystalquest.md)** (JavaScript, MIT, mature, inactive since 2017)
- **[Cubosphere](cubosphere.md)** (C, C++, GPL-3.0, beta)
- **[Cytadela](cytadela.md)** (C++, GPL-3.0, beta, inactive since 2013)
- **[D-Fend Reloaded](d-fend_reloaded.md)** (Pascal, GPL-3.0, mature, inactive since 2015)
- **[D2X-XL](d2x-xl.md)** (C++, Custom, GPL-2.0, mature, inactive since 2015)
- **[Daggerfall Unity](daggerfall_unity.md)** (C#, MIT, mature)
- **[Daimonin](daimonin.md)** (C, GPL-2.0, mature)
- **[Danger from the Deep](danger_from_the_deep.md)** (C++, GPL-2.0, beta, inactive since 2011)
- **[Dark Destiny](dark_destiny.md)** (Java, JavaScript, GPL, mature, inactive since 2016)
- **[Dark Oberon](dark_oberon.md)** (C++, GPL-2.0, mature, inactive since 2009)
- **[DarkCity](darkcity.md)** (PHP, GPL-3.0, mature, inactive since 2012)
- **[DarkPlaces](darkplaces.md)** (C, GPL-2.0, mature, inactive since 2014)
- **[Dash Engine](dash_engine.md)** (D, MIT, mature, inactive since 2015)
- **[Data Storm](data_storm.md)** (C, Apache-2.0, mature, inactive since 2017)
- **[Dave Gnukem](dave_gnukem.md)** (C++, GPL-2.0, mature)
- **[Dawn](dawn.md)** (C++, GPL-3.0, beta, inactive since 2011)
- **[Deathchase 3D](deathchase_3d.md)** (C, GPL-2.0, mature, inactive since 2002)
- **[Decker](decker.md)** (Java, GPL-2.0, beta, inactive since 2013)
- **[Defendguin](defendguin.md)** (C, GPL-2.0, mature, inactive since 2009)
- **[Deity](deity.md)** (Python, GPL-2.0, mature, inactive since 2014)
- **[Deliantra](deliantra.md)** (C, GPL-2.0, mature)
- **[Delta Engine](delta_engine.md)** (C#, Apache-2.0, mature, inactive since 2015)
- **[DelverEngine](delverengine.md)** (Java, Custom, beta)
- **[DemiGod](demigod.md)** (Java, GPL-3.0, beta, inactive since 2013)
- **[Der Clou!](der_clou.md)** (C, Custom, beta, inactive since 2017)
- **[DesktopAdventures](desktopadventures.md)** (C, LGPL-2.1, beta)
- **[DeSmuME](desmume.md)** (C, C++, GPL-2.0, mature, inactive since 2015)
- **[Devana](devana.md)** (PHP, zlib, beta)
- **[Devilution](devilution.md)** (C, C++, Unlicense, mature)
- **[DevilutionX](devilutionx.md)** (C, C++, Unlicense, mature)
- **[DGEngine](dgengine.md)** (C++, Zlib, GPL-3.0, beta)
- **[dhewm3](dhewm3.md)** (C, C++, GPL-3.0, mature)
- **[diablo-js](diablo-js.md)** (Java, JavaScript, MIT, mature)
- **[Digbuild](digbuild.md)** (C, C++, GPL-2.0, beta, inactive since 2011)
- **[Digger Remastered](digger_remastered.md)** (C, GPL-2.0, mature, inactive since 2004)
- **[Digital: A Love Story](digital_a_love_story.md)** (Ren'py, CC-BY-NC-SA, mature)
- **[DNT](dnt.md)** (C++, GPL-3.0, beta, inactive since 2016)
- **[Domination](domination.md)** (Java, GPL-3.0, mature)
- **[Doom Legacy](doom_legacy.md)** (C++, GPL-2.0, mature)
- **[DOOM Retro](doom_retro.md)** (C, C++, GPL-3.0, mature)
- **[DOOM-iOS](doom-ios.md)** (C++, GPL-2.0, mature, inactive since 2012)
- **[Doom64EX](doom64ex.md)** (C, C++, GPL-2.0, mature)
- **[Doomsday](doomsday.md)** (C, C++, GPL-2.0, GPL-3.0, LGPL-3.0, mature)
- **[Dope Wars](dope_wars.md)** (C, GPL-2.0, mature, inactive since 2013)
- **[Doxygen](doxygen.md)** (C++, GPL-2.0, mature)
- **[Dragon History - Dračí Historie](dragon_history-dra_historie.md)** (Pascal, Script, GPL-2.0, mature, inactive since 2010)
- **[Dragon Hunt](dragon_hunt.md)** (Python, GPL-2.0, mature)
- **[DreamChess](dreamchess.md)** (C, GPL-3.0, beta)
- **[DRL](drl.md)** (Lua, Pascal, GPL-2.0, mature)
- **[Duck Marines](duck_marines.md)** (Lua, zlib, mature, inactive since 2016)
- **[Duel Commander](duel_commander.md)** (C, GPL-3.0, beta, inactive since 2009)
- **[Duke3D](duke3d.md)** (C, GPL-2.0, beta, inactive since 2009)
- **[Duke3d_w32](duke3dw32.md)** (C, GPL-2.0, beta, inactive since 2008)
- **[Dune 2 - The Maker](dune_2-the_maker.md)** (Java, MIT, beta)
- **[Dune Dynasty](dune_dynasty.md)** (C, GPL-2.0, mature, inactive since 2014)
- **[Dune II - The Maker](dune_ii-the_maker.md)** (Java, MIT, beta)
- **[Dune Legacy](dune_legacy.md)** (C++, GPL-2.0, mature)
- **[Dungeon Craft](dungeon_craft.md)** (C++, GPL-2.0, mature)
- **[Dungeon Crawl Stone Soup](dungeon_crawl_stone_soup.md)** (C++, Lua, GPL-2.0, mature)
- **[Dungeon Hero](dungeon_hero.md)** (Java, MIT, mature)
- **[Dungeon Mapper](dungeon_mapper.md)** (C++, GPL-3.0, beta, inactive since 2013)
- **[Dungeon Monkey Eternal](dungeon_monkey_eternal.md)** (Python, GPL-2.0, mature, inactive since 2016)
- **[Dungeon Quest](dungeon_quest.md)** (Java, MIT, mature)
- **[Dust Racing 2D](dust_racing_2d.md)** (C, C++, GPL-3.0, mature)
- **[DXX-Rebirth](dxx-rebirth.md)** (C, C++, Python, GPL-3.0, Custom, mature)
- **[EasyRPG Player](easyrpg_player.md)** (C++, GPL-3.0, mature)
- **[Eat The Whistle](eat_the_whistle.md)** (C, ?, mature, inactive since 2017)
- **[Ecksdee](ecksdee.md)** (C++, GPL-2.0, beta, inactive since 2009)
- **[ECWolf](ecwolf.md)** (C++, GPL-2.0, BSD, LGPL-2.1, Libpng, Zlib, bzip2, MIT, IJG, Public Domain, mature)
- **[EDuke32](eduke32.md)** (C, C++, GPL-2.0, mature)
- **[Egoboo](egoboo.md)** (C++, C, GPL-3.0, mature, inactive since 2015)
- **[EmptyEpsilon](emptyepsilon.md)** (C, C++, Lua, GPL-2.0, mature)
- **[Endgame: Singularity](endgame_singularity.md)** (Python, GPL-2.0, beta)
- **[Endless Sky](endless_sky.md)** (C++, GPL-3.0, mature)
- **[Enduro tribute](enduro_tribute.md)** (JavaScript, MIT, mature)
- **[ENIGMA (development environment)](enigma_development_environment.md)** (C++, C, GPL-3.0, mature)
- **[Enigma](enigma.md)** (C, C++, GPL-2.0, mature)
- **[EnTT Pacman](entt_pacman.md)** (C, C++, MIT, mature)
- **[Eos, Dawn of Light: A Space Opera](eos_dawn_of_light_a_space_opera.md)** (Python, MIT, beta, inactive since 2007)
- **[Epiar](epiar.md)** (C, C++, Lua, GPL-2.0, beta)
- **[EPOH](epoh.md)** (JavaScript, MIT, beta)
- **[erampage](erampage.md)** (C, GPL-2.0, beta, inactive since 2015)
- **[Erebus](erebus.md)** (C++, GPL-3.0, beta)
- **[ET: Legacy](et_legacy.md)** (C, C++, Lua, GPL-3.0, mature)
- **[Eternal Lands](eternal_lands.md)** (C, C++, Custom, mature)
- **[EternalWinterWars](eternalwinterwars.md)** (Java, MIT, beta, inactive since 2014)
- **[Evil Cult](evil_cult.md)** (Haxe, JavaScript, GPL-3.0, mature)
- **[Evol Online](evol_online.md)** (C, GPL-3.0, mature)
- **[Executive Man](executive_man.md)** (JavaScript, Custom, mature, inactive since 2017)
- **[Exult](exult.md)** (C++, GPL-2.0, mature)
- **[ezQuake](ezquake.md)** (C, C++, GPL-2.0, mature)
- **[F-1 Spirit](f-1_spirit.md)** (C++, ??, beta, inactive since 2009)
- **[F.LF](flf.md)** (JavaScript, ?, mature)
- **[Fall of Imiryn](fall_of_imiryn.md)** (C++, Python, GPL-3.0, beta, inactive since 2009)
- **[Fallen Spire](fallen_spire.md)** (Python, GPL-3.0, beta, inactive since 2009)
- **[Falling Time](falling_time.md)** (C, C++, GPL-2.0, mature)
- **[Fanwor](fanwor.md)** (C, GPL-2.0, mature)
- **[FAR Colony](far_colony.md)** (Pascal, GPL-3.0, beta, inactive since 2014)
- **[First Strike](first_strike.md)** (Java, MIT, mature)
- **[Fish Fillets - Next Generation](fish_fillets-next_generation.md)** (C++, GPL-2.0, mature)
- **[Flare](flare.md)** (C++, Java, GPL-3.0, mature)
- **[FlightGear](flightgear.md)** (C++, GPL-2.0, mature)
- **[Flixel](flixel.md)** (ActionScript, MIT, mature)
- **[Fluid Table Tennis](fluid_table_tennis.md)** (JavaScript, MIT, mature, inactive since 2013)
- **[fonline](fonline.md)** (C, C++, GPL-3.0, beta)
- **[FQuake3](fquake3.md)** (F#, GPL-2.0, beta, inactive since 2014)
- **[Free Heroes 2](free_heroes_2.md)** (C++, GPL-2.0, beta, inactive since 2015)
- **[Free in the Dark (engine)](free_in_the_dark_engine.md)** (C, C++, GPL-2.0, beta)
- **[Free Mars](free_mars.md)** (Java, GPL-3.0, mature)
- **[Free Space Colonization](free_space_colonization.md)** (C, GPL-2.0, beta)
- **[freeablo](freeablo.md)** (C++, GPL-3.0, beta)
- **[freeaoe](freeaoe.md)** (C++, GPL-3.0, beta)
- **[FreeBlocks](freeblocks.md)** (C, Java, GPL-3.0, beta, inactive since 2015)
- **[Freeciv Alpha Centauri project](freeciv_alpha_centauri_project.md)** (C, GPL-2.0, beta, inactive since 2003)
- **[Freeciv WebGL](freeciv_webgl.md)** (JavaScript, Java, AGPL-3.0, mature)
- **[Freeciv](freeciv.md)** (C, GPL-2.0, mature)
- **[FreeCol](freecol.md)** (Java, GPL-2.0, mature)
- **[FreeCS](freecs.md)** (QuakeC, GPL-2.0, mature)
- **[Freedoom](freedoom.md)** (Not applicable, Not applicable, beta)
- **[FreedroidRPG](freedroidrpg.md)** (C, C++, Lua, GPL-2.0, mature)
- **[FreeFalcon](freefalcon.md)** (C, C++, 2-clause BSD, inactive since 2014)
- **[freegish](freegish.md)** (C, GPL-2.0, beta, inactive since 2017)
- **[Freekick 3](freekick_3.md)** (C++, Python, GPL-3.0, mature, inactive since 2015)
- **[FreeLords](freelords.md)** (Java, GPL-2.0, beta)
- **[Freeminer](freeminer.md)** (C++, Lua, GPL-3.0, beta)
- **[Freenukum Jump'n Run](freenukum_jumpn_run.md)** (C, GPL-3.0, beta, inactive since 2009)
- **[FreeOrion](freeorion.md)** (C++, Python, GPL-2.0, beta)
- **[FreePrince](freeprince.md)** (C, GPL-2.0, beta, inactive since 2011)
- **[FreeRails](freerails.md)** (Java, C++, GPL-2.0, beta, inactive since 2008)
- **[FreeRCT](freerct.md)** (C++, GPL-2.0, beta, inactive since 2016)
- **[Freeserf](freeserf.md)** (C, C++, GPL-3.0, mature)
- **[FreeSiege](freesiege.md)** (C++, GPL-3.0, beta)
- **[FreeSims](freesims.md)** (C#, MPL-2.0, beta)
- **[FreeSO](freeso.md)** (C#, MPL-2.0, beta)
- **[Freestars](freestars.md)** (C++, GPL-2.0, beta, inactive since 2008)
- **[FreeSynd](freesynd.md)** (C++, GPL-2.0, beta, inactive since 2017)
- **[FreeTrain](freetrain.md)** (C#, LGPL-2.1, beta, inactive since 2009)
- **[FreeType](freetype.md)** (C, GPL-2.0, Custom, mature)
- **[freeVikings](freevikings.md)** (Ruby, GPL-2.0, beta)
- **[Frets on Fire X](frets_on_fire_x.md)** (Python, GPL-2.0, mature)
- **[Frets on Fire](frets_on_fire.md)** (Python, GPL-2.0, mature, inactive since 2008)
- **[Friking Shark](friking_shark.md)** (C++, GPL-3.0, mature)
- **[Froggix](froggix.md)** (Python, GPL-3.0, beta, inactive since 2009)
- **[Frozen Bubble](frozen_bubble.md)** (Perl, GPL-2.0, mature, inactive since 2012)
- **[Fujo](fujo.md)** (Python, CC-BY-SA-4.0, mature, inactive since 2014)
- **[Galaxy Forces V2](galaxy_forces_v2.md)** (C++, ?, mature)
- **[GalaxyMage Redux](galaxymage_redux.md)** (Python, GPL-2.0, beta, inactive since 2011)
- **[GalaxyNG](galaxyng.md)** (C, GPL-2.0, mature, inactive since 2005)
- **[GameLV](gamelv.md)** (C++, GPL-2.0, beta)
- **[Gang Garrison 2](gang_garrison_2.md)** (Game Maker Script, MPL, mature)
- **[GDash](gdash.md)** (C++, MIT, beta)
- **[GearHead](gearhead.md)** (Pascal, LGPL-2.1, Apache-2.0, mature)
- **[Gee Whiz](gee_whiz.md)** (C, GPL-2.0, beta, inactive since 2004)
- **[GemRB](gemrb.md)** (C++, Python, GPL-2.0, mature)
- **[ges-code](ges-code.md)** (C, C++, GPL-3.0, mature)
- **[Gift Grabber](gift_grabber.md)** (JavaScript, Apache-2.0, mature)
- **[Gigalomania](gigalomania.md)** (C++, GPL-2.0, mature)
- **[Glest](glest.md)** (C++, GPL-2.0, mature, inactive since 2009)
- **[Globulation 2](globulation_2.md)** (C++, GPL-3.0, mature)
- **[glPortal](glportal.md)** (C++, zlib, beta)
- **[GLtron](gltron.md)** (C, GPL, beta, inactive since 2017)
- **[GM Tools](gm_tools.md)** (C++, GPL-2.0, beta, inactive since 2004)
- **[Gnomescroll](gnomescroll.md)** (C, C++, Python, GPL-3.0, beta, inactive since 2013)
- **[GNU FreeDink](gnu_freedink.md)** (C, C++, GPL-3.0, mature)
- **[Goblin Camp](goblin_camp.md)** (C++, GPL-3.0, beta, inactive since 2012)
- **[Goblin Hack](goblin_hack.md)** (C++, GPL-2.0, beta, inactive since 2009)
- **[Godot](godot.md)** (C, C++, MIT, mature)
- **[Golly](golly.md)** (C++, Java, GPL-2.0, mature)
- **[Gorc](gorc.md)** (C++, Apache-2.0, beta)
- **[Gorillas-rs](gorillas-rs.md)** (Rust, MIT, beta)
- **[Gorillas](gorillas.md)** (Objective-C, JavaScript, Java Research License, mature, inactive since 2014)
- **[GPL Arcade Volleyball](gpl_arcade_volleyball.md)** (C++, GPL-2.0, beta, inactive since 2006)
- **[Grabble](grabble.md)** (Java, ?, mature, inactive since 2006)
- **[Greenius' Civil War](greenius_civil_war.md)** (C++, GPL-2.0, beta, inactive since 2001)
- **[Griefly](griefly.md)** (C++, Go, Python, MIT, beta)
- **[Grimsonland](grimsonland.md)** (JavaScript, ?, mature, inactive since 2017)
- **[Grit Game Engine](grit_game_engine.md)** (C++, Python, MIT, beta)
- **[Grobots](grobots.md)** (C++, GPL-2.0, mature, inactive since 2014)
- **[GUSANOS](gusanos.md)** (C++, GPL-2.0, beta, inactive since 2006)
- **[Gusty's Serpents](gustys_serpents.md)** (C++, GPL-3.0, beta, inactive since 2014)
- **[Gweled](gweled.md)** (C, GPL-2.0, mature)
- **[GZDoom](gzdoom.md)** (C, C++, GPL-3.0, mature)
- **[H-Craft Championship](h-craft_championship.md)** (C++, zlib, mature, inactive since 2015)
- **[H-World](h-world.md)** (C, Lua, GPL-2.0, beta, inactive since 2005)
- **[Hale](hale.md)** (Java, GPL-2.0, beta, inactive since 2014)
- **[Hammer of Thyrion](hammer_of_thyrion.md)** (C, GPL-2.0, mature)
- **[Hardwar](hardwar.md)** (C++, GPL-3.0, beta, inactive since 2015)
- **[HarfBuzz](harfbuzz.md)** (C++, MIT, mature)
- **[Harris](harris.md)** (C, Python, GPL-3.0, beta)
- **[HaxeFlixel](haxeflixel.md)** (Haxe, MIT, mature)
- **[Haxima](haxima.md)** (C++, GPL-3.0, beta)
- **[Head over Heels](head_over_heels.md)** (C++, GPL-3.0, mature)
- **[Heart of the Alien](heart_of_the_alien.md)** (C, GPL-2.0, beta, inactive since 2005)
- **[Hedgewars](hedgewars.md)** (Lua, C, C++, Pascal, Haskell, GPL-2.0, mature)
- **[Hematite](hematite.md)** (Rust, MIT, beta)
- **[Hero of Allacrost](hero_of_allacrost.md)** (C++, Lua, GPL-2.0, mature)
- **[Heroes of Wesnoth](heroes_of_wesnoth.md)** (C++, GPL-3.0, beta, inactive since 2010)
- **[Heroes of Wing Commander](heroes_of_wing_commander.md)** (Python, GPL-3.0, beta, inactive since 2014)
- **[Hex Game](hex_game.md)** (C++, MIT, beta)
- **[HexGL](hexgl.md)** (JavaScript, CoffeeScript, MIT, mature, inactive since 2016)
- **[Hexoshi](hexoshi.md)** (Python, GPL-3.0, beta, inactive since 2016)
- **[Hextris](hextris.md)** (JavaScript, GPL-3.0, mature)
- **[Hexwar](hexwar.md)** (Ruby, JavaScript, MIT, beta, inactive since 2012)
- **[Hocoslamfy](hocoslamfy.md)** (C, C++, GPL-2.0, beta, inactive since 2016)
- **[HoDoKu](hodoku.md)** (Java, GPL-3.0, mature, inactive since 2013)
- **[HolySpirit](holyspirit.md)** (C++, GPL-3.0, beta, inactive since 2013)
- **[HoverRace](hoverrace.md)** (C++, Custom NC, mature, inactive since 2016)
- **[Hovertank3D](hovertank3d.md)** (C++, Assembly, GPL-2.0, mature, inactive since 2014)
- **[HTML5 Pacman](html5_pacman.md)** (JavaScript, WTFPL, mature, inactive since 2013)
- **[HyperRogue](hyperrogue.md)** (C++, GPL-2.0, mature)
- **[I Have No Tomatoes](i_have_no_tomatoes.md)** (C++, zlib, mature, inactive since 2004)
- **[ICBM3D](icbm3d.md)** (C, ?, beta, inactive since 1998)
- **[Ice Breaker](ice_breaker.md)** (C, GPL-2.0, mature, inactive since 2003)
- **[Iceball](iceball.md)** (C, Lua, GPL-3.0, inactive since 2017)
- **[Ilarion](ilarion.md)** (C++, Java, Lua, GPL-3.0, mature)
- **[Imperium](imperium.md)** (?, ?, mature)
- **[Inexor](inexor.md)** (C++, JavaScript, zlib, beta, inactive since 2018)
- **[Infiniminer](infiniminer.md)** (C#, MIT, mature, inactive since 2016)
- **[IO Reboot](io_reboot.md)** (C#, MIT, mature, inactive since 2017)
- **[ioquake3](ioquake3.md)** (C, GPL-2.0, mature)
- **[Iris2](iris2.md)** (C, C++, Lua, GPL-3.0, beta, inactive since 2017)
- **[Iron Seed](iron_seed.md)** (Pascal, GPL-3.0, mature, inactive since 2013)
- **[irrlamb](irrlamb.md)** (C, C++, GPL-3.0, mature)
- **[Irrlicht Engine](irrlicht_engine.md)** (C++, C, zlib, mature)
- **[Isometric Turn-Based Strategy](isometric_turn-based_strategy.md)** (Python, MIT, beta)
- **[Iter Vehemens ad Necem](iter_vehemens_ad_necem.md)** (C++, GPL-2.0, beta)
- **[Jagged Alliance 2 Stracciatella](jagged_alliance_2_stracciatella.md)** (C, C++, Custom, mature)
- **[Jake2](jake2.md)** (Java, GPL-2.0, beta, inactive since 2006)
- **[JaNaG - Java Name Generator](janag-java_name_generator.md)** (Java, GPL-3.0, mature, inactive since 2016)
- **[javascript-E.T.](javascript-et.md)** (JavaScript, Assembly, MIT, beta, inactive since 2017)
- **[Jazz² Resurrection](jazz_resurrection.md)** (C#, JavaScript, GPL-3.0, mature)
- **[JediOutcastLinux](jedioutcastlinux.md)** (C, C++, GPL-2.0, mature)
- **[Jet-Story](jet-story.md)** (Assembly, C, C++, MIT, beta)
- **[jewelthief](jewelthief.md)** (Java, GPL-3.0, mature, inactive since 2016)
- **[JFDuke3D](jfduke3d.md)** (C, GPL-2.0, beta, inactive since 2005)
- **[JiGS Interactive Game System](jigs_interactive_game_system.md)** (JavaScript, PHP, GPL-3.0, beta)
- **[jMonkeyEngine](jmonkeyengine.md)** (Java, 3-clause BSD, mature)
- **[JonoF's Shadow Warrior Port (JFSW)](jonofs_shadow_warrior_port_jfsw.md)** (C, GPL-2.0, beta, inactive since 2005)
- **[JQuest](jquest.md)** (Java, GPL-2.0, beta, inactive since 2006)
- **[JSettlers](jsettlers.md)** (Java, GPL-3.0, mature)
- **[jsFO](jsfo.md)** (JavaScript, Python, Apache-2.0, beta, inactive since 2017)
- **[Julius](julius.md)** (C, C++, AGPL-3.0, mature)
- **[Jump'n'Bump](jumpnbump.md)** (C, GPL-2.0, mature, inactive since 2004)
- **[KaM Remake](kam_remake.md)** (Pascal, AGPL-3.0, mature)
- **[KAtomic](katomic.md)** (C++, GPL-2.0, mature)
- **[Keen Dreams](keen_dreams.md)** (C, Assembly, C++, GPL-2.0, mature, inactive since 2014)
- **[KGoldrunner](kgoldrunner.md)** (C++, GPL-2.0, mature)
- **[kiki the nano bot](kiki_the_nano_bot.md)** (C++, Public domain, mature, inactive since 2007)
- **[Kingdoms](kingdoms.md)** (C++, GPL-3.0, beta, inactive since 2014)
- **[KittenMaxit](kittenmaxit.md)** (Java, MIT, beta)
- **[KKnD](kknd.md)** (C#, GPL-3.0, beta)
- **[KnightOfWor](knightofwor.md)** (Java, GPL-3.0, beta, inactive since 2015)
- **[Knights](knights.md)** (C++, GPL-3.0, beta, inactive since 2014)
- **[Kobold's Quest 2](kobolds_quest_2.md)** (Python, LGPL-3.0, beta, inactive since 2011)
- **[KQ Lives](kq_lives.md)** (C, GPL-2.0, beta, inactive since 2011)
- **[Krystal Drop](krystal_drop.md)** (C++, GPL-2.0, beta, inactive since 2004)
- **[l-echo](l-echo.md)** (C++, GPL-3.0, beta, inactive since 2016)
- **[Labyrinth of Worlds](labyrinth_of_worlds.md)** (C++, LGPL-3.0, beta, inactive since 2010)
- **[ladder](ladder-2.md)** (Go, MIT, beta, inactive since 2016)
- **[Ladder](ladder.md)** (Java, GPL-2.0, mature, inactive since 2005)
- **[Land of Fire](land_of_fire.md)** (Custom, GPL-2.0, beta)
- **[LastTry](lasttry.md)** (Java, MIT, beta, inactive since 2017)
- **[Lemmings.ts](lemmingsts.md)** (TypeScript, MIT, mature)
- **[Lemmini](lemmini.md)** (Java, Apache-2.0, beta, inactive since 2017)
- **[LGames](lgames.md)** (C++, GPL-2.0, mature)
- **[LGeneral](lgeneral.md)** (C, GPL-2.0, mature, inactive since 2017)
- **[libGDX](libgdx.md)** (Java, C++, C, Apache-2.0, mature)
- **[libpng](libpng.md)** (C, Custom, mature)
- **[Librelancer](librelancer.md)** (C, C#, MIT, beta)
- **[Libxml2](libxml2.md)** (C, MIT, mature)
- **[Lightweight Java Game Library](lightweight_java_game_library.md)** (Kotlin, C, 3-clause BSD, mature)
- **[LinCity-NG](lincity-ng.md)** (C++, GPL-2.0, mature)
- **[Lincity](lincity.md)** (C, GPL-2.0, mature, inactive since 2005)
- **[Linley's Dungeon Crawl](linleys_dungeon_crawl.md)** (C, Custom, mature, inactive since 2006)
- **[Linwarrior 3D](linwarrior_3d.md)** (C++, Apache-2.0, mature, inactive since 2010)
- **[Lionheart Remake](lionheart_remake.md)** (Java, GPL-3.0, beta, inactive since 2018)
- **[Lips of Suna](lips_of_suna.md)** (C, GPL-3.0, beta, inactive since 2014)
- **[Liquid War](liquid_war.md)** (C, GPL-3.0, mature, inactive since 2015)
- **[Lix](lix.md)** (D, C++, CC0, beta)
- **[LordsAWar!](lordsawar.md)** (C++, GPL-3.0, mature)
- **[Lose Your Marbles](lose_your_marbles.md)** (JavaScript, MIT, mature, inactive since 2014)
- **[lttp-phaser](lttp-phaser.md)** (TypeScript, JavaScript, MIT, beta, inactive since 2016)
- **[Lua](lua.md)** (C, MIT, mature)
- **[Lugaru](lugaru.md)** (C++, GPL-2.0, mature)
- **[Lumix Engine](lumix_engine.md)** (C++, MIT, beta)
- **[LZMA SDK](lzma_sdk.md)** (C, LGPL-2.0, mature)
- **[LÖVE](lve.md)** (C++, zlib, mature)
- **[M.E.W.L.](mewl.md)** (C++, GPL-2.0, beta, inactive since 2015)
- **[Machinations](machinations.md)** (C++, GPL-2.0, beta, inactive since 2003)
- **[Maelstrom](maelstrom.md)** (C, C++, GPL-2.0, mature, inactive since 2002)
- **[Magarena](magarena.md)** (Java, Groovy, GPL-3.0, mature)
- **[Mana](mana.md)** (C++, GPL-2.0, beta)
- **[Manic Digger](manic_digger.md)** (C#, Public domain, Unlicense, mature, inactive since 2017)
- **[Maratis](maratis.md)** (C++, GPL-2.0, beta)
- **[Marblez](marblez.md)** (C#, MIT, beta, inactive since 2017)
- **[Mari0](mari0.md)** (Lua, CC-BY-NC-SA-3.0, mature, inactive since 2012)
- **[Mars, Land of No Mercy](mars_land_of_no_mercy.md)** (C++, GPL-2.0, beta, inactive since 2008)
- **[Maxit](maxit.md)** (C++, ?, mature, inactive since 2014)
- **[Me and My Shadow](me_and_my_shadow.md)** (C++, GPL-3.0, beta)
- **[Mechanized Assault & eXploration Reloaded](mechanized_assault_exploration_reloaded.md)** (C++, C, GPL-2.0, beta)
- **[MechCommander 2 Omnitech](mechcommander_2_omnitech.md)** (C++, Ms-PL, beta, inactive since 2013)
- **[Mega Mario](mega_mario.md)** (C++, LGPL-2.1, mature, inactive since 2012)
- **[MegaGlest](megaglest.md)** (C, C++, GPL-3.0, mature)
- **[MegaMek](megamek.md)** (Java, GPL-2.0, mature)
- **[Mercenary Commander](mercenary_commander.md)** (Java, 3-clause BSD, beta, inactive since 2010)
- **[Meridian 59](meridian_59.md)** (C++, C, GPL-2.0, mature)
- **[Meritous](meritous.md)** (C, GPL-3.0, mature, inactive since 2008)
- **[Metal Mech](metal_mech.md)** (PHP, GPL-2.0, beta, inactive since 2006)
- **[Mice Men: Remix](mice_men_remix.md)** (Java, LGPL-3.0, mature, inactive since 2016)
- **[Micropolis](micropolis.md)** (C++, Java, Python, GPL-3.0, mature, inactive since 2015)
- **[micropolisJS](micropolisjs.md)** (JavaScript, GPL-3.0, mature)
- **[Microracers](microracers.md)** (C++, GPL-2.0, beta, inactive since 2005)
- **[MicroWar 2.0](microwar_20.md)** (Python, 3-clause BSD, mature, inactive since 2009)
- **[MineCraft-One-Week-Challenge](minecraft-one-week-challenge.md)** (C++, MIT, beta)
- **[Minesweeper.Zone](minesweeperzone.md)** (JavaScript, PHP, MIT, mature)
- **[Minetest](minetest.md)** (C, C++, Lua, LGPL-2.1, mature)
- **[Mininim](mininim.md)** (C, GPL-3.0, beta, inactive since 2017)
- **[Mirror Magic](mirror_magic.md)** (C, GPL-2.0, mature)
- **[mk.js](mkjs.md)** (JavaScript, MIT, beta)
- **[mkxp](mkxp.md)** (C++, C, GPL-2.0, mature)
- **[Mocha Doom](mocha_doom.md)** (Java, GPL-3.0, beta, inactive since 2012)
- **[MonoGame](monogame.md)** (C#, Ms-PL, MIT, mature)
- **[Monster Generator](monster_generator.md)** (Java, MIT, mature)
- **[Monsters and Mushrooms](monsters_and_mushrooms.md)** (Python, GPL-2.0, mature, inactive since 2010)
- **[Monstrosity](monstrosity.md)** (Python, MIT, mature)
- **[Moria](moria.md)** (C, GPL-3.0, mature)
- **[Morpheus Web Remake](morpheus_web_remake.md)** (Javascript, MIT, beta)
- **[movbizz](movbizz.md)** (PHP, JavaScript, MIT, beta, inactive since 2015)
- **[Mpango](mpango.md)** (Java, GPL-2.0, beta, inactive since 2013)
- **[Mr.Boom](mrboom.md)** (C++, MIT, mature)
- **[Murder In The Public Domain](murder_in_the_public_domain.md)** (C++, GPL-3.0, mature, inactive since 2013)
- **[Naev](naev.md)** (C, Lua, GPL-3.0, mature)
- **[NBlood](nblood.md)** (C, C++, Lua, GPL-2.0, mature)
- **[Netacka](netacka.md)** (C, MIT, mature)
- **[NetHack](nethack.md)** (C, Custom, mature)
- **[NetPanzer](netpanzer.md)** (C++, GPL-2.0, beta)
- **[Netrek](netrek.md)** (C, Custom, mature, inactive since 2009)
- **[NetStatsBaseball](netstatsbaseball.md)** (C, Public domain, mature)
- **[Neverball](neverball.md)** (C, C++, GPL-2.0, mature)
- **[Nexuiz](nexuiz.md)** (C++, GPL-2.0, mature)
- **[NFSIISE](nfsiise.md)** (C, MIT, mature)
- **[Nighthawk](nighthawk.md)** (C++, GPL-2.0, mature, inactive since 2004)
- **[NLarn](nlarn.md)** (C, Lua, GPL-3.0, mature)
- **[NStars!](nstars.md)** (C#, GPL-2.0, beta, inactive since 2004)
- **[NullpoMino](nullpomino.md)** (Java, 3-clause BSD, mature)
- **[Nuncabola](nuncabola.md)** (Java, GPL-2.0, beta)
- **[Nuvie](nuvie.md)** (C, C++, Lua, GPL-2.0, beta, inactive since 2018)
- **[NXEngine-evo](nxengine-evo.md)** (C++, GPL-3.0, mature)
- **[NXEngine](nxengine.md)** (C, C++, GPL-3.0, mature)
- **[nXtank](nxtank.md)** (Python, GPL-3.0, beta, inactive since 2010)
- **[O.H.R.RPG.C.E.](ohrrpgce.md)** (Basic, GPL-2.0, mature)
- **[Octaforge](octaforge.md)** (C++, Custom, mature)
- **[Odamex](odamex.md)** (C, C++, GPL-2.0, beta)
- **[OGRE3D](ogre3d.md)** (C++, MIT, mature)
- **[Omnispeak](omnispeak.md)** (C, GPL-2.0, mature)
- **[One Way To Go](one_way_to_go.md)** (Lua, GPL-3.0, mature, inactive since 2011)
- **[Oolite](oolite.md)** (Objective-C, C, JavaScript, GPL-2.0, mature)
- **[Open AL Soft](open_al_soft.md)** (C, LGPL-2.0, mature)
- **[Open AL](open_al.md)** (C, Proprietary, mature)
- **[Open Apocalypse](open_apocalypse.md)** (C++, MIT, mature)
- **[Open Creatures](open_creatures.md)** (C, C++, Python, LGPL-2.1, beta, inactive since 2010)
- **[Open Cube](open_cube.md)** (C++, zlib, beta, inactive since 2017)
- **[Open Fodder](open_fodder.md)** (C, C++, GPL-3.0, mature)
- **[Open Game Engine](open_game_engine.md)** (C++, LGPL-2.1, beta, inactive since 2008)
- **[Open Hexagon](open_hexagon.md)** (C++, AFL-3.0, mature)
- **[Open Horizon](open_horizon.md)** (C++, MIT, beta)
- **[Open Imperium Galactica](open_imperium_galactica.md)** (Java, LGPL-3.0, mature)
- **[Open Jumpgate](open_jumpgate.md)** (C++, GPL-2.0, beta, inactive since 2017)
- **[Open Legend RPG](open_legend_rpg.md)** (Text, Custom, mature)
- **[Open Meridian](open_meridian.md)** (C, C++, GPL-2.0, mature)
- **[Open Panzer](open_panzer.md)** (JavaScript, GPL-2.0, mature)
- **[Open Rails](open_rails.md)** (C#, GPL-3.0, mature)
- **[Open Rodent's Revenge](open_rodents_revenge.md)** (C++, GPL-3.0, beta, inactive since 2018)
- **[Open RPG Maker](open_rpg_maker.md)** (C++, GPL-3.0, beta, inactive since 2014)
- **[Open RSC](open_rsc.md)** (Java, GPL-3.0, mature)
- **[Open Soccer Star](open_soccer_star.md)** (PHP, GPL-3.0, beta)
- **[Open Surge](open_surge.md)** (C, GPL-3.0, beta)
- **[Open Syobon Action](open_syobon_action.md)** (C++, ?, beta, inactive since 2011)
- **[Open Tibia](open_tibia.md)** (C++, GPL-2.0, beta, inactive since 2014)
- **[Open Yahtzee](open_yahtzee.md)** (C++, GPL-2.0, mature, inactive since 2016)
- **[Open Zelda](open_zelda.md)** (C, C++, zlib, mature, inactive since 2015)
- **[openage](openage.md)** (C++, Python, GPL-3.0, beta)
- **[OpenArena](openarena.md)** (C, GPL-2.0, mature, inactive since 2012)
- **[OpenBlok](openblok.md)** (C++, GPL-3.0, beta)
- **[OpenBlox](openblox.md)** (Python, Lua, GPL-3.0, beta, inactive since 2011)
- **[OpenC1](openc1.md)** (C#, ?, beta, inactive since 2014)
- **[OpenCity](opencity.md)** (C++, GPL-2.0, beta, inactive since 2015)
- **[OpenClaw](openclaw.md)** (C++, GPL-3.0, mature)
- **[OpenClonk](openclonk.md)** (C, C++, ISC, mature)
- **[OpenCrystalCaves](opencrystalcaves.md)** (C++, MIT, beta, inactive since 2017)
- **[OpenDominion](opendominion.md)** (PHP, AGPL-3.0, beta)
- **[openDOW](opendow.md)** (C, GPL-3.0, beta)
- **[OpenDUNE](opendune.md)** (C, GPL-2.0, mature)
- **[OpenDungeons](opendungeons.md)** (C++, GPL-3.0, beta)
- **[OpenEtG](openetg.md)** (JavaScript, MIT, beta)
- **[OpenFire](openfire.md)** (C, MIT, beta, inactive since 2018)
- **[OpenFL](openfl.md)** (Haxe, MIT, mature)
- **[OpenGGS](openggs.md)** (C++, GPL-2.0, beta, inactive since 2017)
- **[OpenGL Test Drive Remake](opengl_test_drive_remake.md)** (C, C++, GPL-3.0, mature, inactive since 2015)
- **[Openglad](openglad.md)** (C++, GPL-2.0, mature, inactive since 2004)
- **[OpenHoMM](openhomm.md)** (C++, GPL-3.0, beta, inactive since 2010)
- **[OpenJazz](openjazz.md)** (C++, GPL-2.0, beta)
- **[OpenJK](openjk.md)** (C, C++, GPL-2.0, beta)
- **[OpenLara](openlara.md)** (C++, 2-clause BSD, mature)
- **[OpenLiero](openliero.md)** (C++, Custom, mature, inactive since 2015)
- **[OpenLieroX](openlierox.md)** (C++, LGPL-2.0, mature)
- **[OpenLoco](openloco.md)** (C++, MIT, mature)
- **[OpenMC2](openmc2.md)** (C++, GPL-3.0, beta, inactive since 2018)
- **[OpenMoM](openmom.md)** (C, C++, GPL-3.0, beta)
- **[OpenMOO2](openmoo2.md)** (Python, GPL-2.0, beta, inactive since 2011)
- **[OpenMortal](openmortal.md)** (C++, GPL-2.0, beta, inactive since 2006)
- **[OpenMW](openmw.md)** (C++, GPL-3.0, mature)
- **[OpenNFS](opennfs.md)** (C, C++, MIT, beta)
- **[OpenNotrium](opennotrium.md)** (C++, GPL-3.0, beta)
- **[OpenOMF](openomf.md)** (C, C++, MIT, beta)
- **[OpenRA](openra.md)** (C#, GPL-3.0, mature)
- **[OpenRaider](openraider.md)** (C, C++, GPL-2.0, beta, inactive since 2015)
- **[OpenRCT2](openrct2.md)** (C++, GPL-3.0, mature)
- **[OpenRoads](openroads.md)** (TypeScript, Javascript, MIT, mature, inactive since 2014)
- **[OpenRPG](openrpg.md)** (Python, GPL-2.0, mature, inactive since 2013)
- **[OpenSAGE](opensage.md)** (C#, LGPL-3.0, beta)
- **[OpenSC2K](opensc2k.md)** (JavaScript, GPL-3.0, beta)
- **[OpenSkyscraper](openskyscraper.md)** (C++, GPL-2.0, beta)
- **[OpenSoccer](opensoccer.md)** (PHP, GPL-3.0, beta)
- **[OpenSpades](openspades.md)** (C, C++, AngelScript, GPL-3.0, beta)
- **[OpenSR](opensr.md)** (C++, GPL-3.0, beta, inactive since 2017)
- **[OpenSSL](openssl.md)** (C, Custom, mature)
- **[OpenSWE1R](openswe1r.md)** (C, C++, GPL-2.0, beta)
- **[OpenTitus](opentitus.md)** (C, GPL-3.0, beta, inactive since 2014)
- **[OpenTomb](opentomb.md)** (C, C++, Lua, LGPL-3.0, beta)
- **[OpenTriad](opentriad.md)** (Java, GPL-3.0, beta, inactive since 2017)
- **[OpenTTD](openttd.md)** (C++, GPL-2.0, mature)
- **[OpenTyrian](opentyrian.md)** (C, GPL-2.0, beta, inactive since 2018)
- **[OpenWebSoccer-Sim](openwebsoccer-sim.md)** (PHP, LGPL-3.0, mature)
- **[OpenXcom](openxcom.md)** (C++, GPL-3.0, mature)
- **[Operation Citadel](operation_citadel.md)** (C++, GPL-2.0, beta, inactive since 2000)
- **[OpMon](opmon.md)** (C++, GPL-3.0, beta)
- **[Orbit-Hopper](orbit-hopper.md)** (C++, GPL-2.0, mature, inactive since 2019)
- **[Orbium](orbium.md)** (JavaScript, GPL-2.0, mature, inactive since 2018)
- **[ORIENT](orient.md)** (C#, Java, GPL-2.0, mature, inactive since 2009)
- **[orona](orona.md)** (CoffeeScript, GPL-2.0, beta, inactive since 2012)
- **[Orx](orx.md)** (C, zlib, mature)
- **[Ostrich Riders](ostrich_riders.md)** (C++, GPL-3.0, beta)
- **[Other-Life](other-life.md)** (C, C++, Custom, beta)
- **[Our Personal Space](our_personal_space.md)** (Ren'py, GPL-3.0, mature)
- **[Outer Space](outer_space.md)** (Python, GPL-2.0, beta)
- **[Outpost HD](outpost_hd.md)** (C++, 3-clause BSD, beta)
- **[pacman-canvas](pacman-canvas.md)** (JavaScript, CC-BY-SA-4.0, mature, inactive since 2018)
- **[PainTown](paintown.md)** (C++, Java, Python, 3-clause BSD, mature)
- **[Panda 3D](panda_3d.md)** (C++, C, 3-clause BSD, mature)
- **[Panel Attack](panel_attack.md)** (Lua, zlib, beta)
- **[Pang Zero](pang_zero.md)** (Perl, GPL-2.0, beta, inactive since 2007)
- **[Paper Isaac](paper_isaac.md)** (ooc, MIT, beta, inactive since 2015)
- **[PARPG](parpg.md)** (Python, GPL-3.0, beta, inactive since 2012)
- **[Pasang Emas](pasang_emas.md)** (Vala, GPL-3.0, mature)
- **[Pax Britannica](pax_britannica.md)** (Lua, C, MIT, mature)
- **[PCGen](pcgen.md)** (Java, LGPL-2.1, mature)
- **[Phantasy Star Rebirth](phantasy_star_rebirth.md)** (C++, GPL-3.0, beta, inactive since 2013)
- **[Pingus](pingus.md)** (C++, GPL-3.0, mature)
- **[Pioneer](pioneer.md)** (C, C++, Lua, Apache-2.0, GPL-3.0, mature)
- **[Pioneers](pioneers.md)** (C, GPL-2.0, mature)
- **[Pizza Business](pizza_business.md)** (C++, GPL-2.0, mature, inactive since 2003)
- **[pkg-config](pkg-config.md)** (C, GPL-2.0, mature)
- **[PlaneShift](planeshift.md)** (C++, GPL-2.0, mature)
- **[Planetary Hoppers](planetary_hoppers.md)** (Java, GPL-2.0, beta, inactive since 2003)
- **[PokerTH](pokerth.md)** (C++, AGPL-3.0, mature, inactive since 2017)
- **[Polis](polis.md)** (Java, GPL-3.0, mature, inactive since 2016)
- **[Polycode](polycode.md)** (C, C++, MIT, beta)
- **[Project Helena](project_helena.md)** (Pascal, GPL-3.0, beta)
- **[Pthreads-win32](pthreads-win32.md)** (C, LGPL-2.1, mature)
- **[pygame](pygame.md)** (C, Python, LGPL-2.1, mature)
- **[PyKaraoke](pykaraoke.md)** (Python, LGPL-2.1, beta, inactive since 2011)
- **[Pymapper](pymapper.md)** (Python, GPL-3.0, mature)
- **[pyORPG](pyorpg.md)** (Python, MIT, beta, inactive since 2015)
- **[PySol](pysol.md)** (Python, GPL-2.0, mature, inactive since 2004)
- **[Qt](qt.md)** (C++, LGPL-3.0, mature)
- **[Quad-engine](quad-engine.md)** (Pascal, MIT, beta)
- **[Rabbit Escape](rabbit_escape.md)** (Java, GPL-2.0, mature)
- **[Radakan](radakan.md)** (Python, Custom, beta, inactive since 2014)
- **[Ragel](ragel.md)** (C++, MIT, mature)
- **[Rails: an 18xx game system](rails_an_18xx_game_system.md)** (Java, GPL-2.0, mature)
- **[ransack](ransack.md)** (Python, MIT, mature, inactive since 2016)
- **[Red Eclipse](red_eclipse.md)** (C++, zlib, mature)
- **[REGoth](regoth.md)** (C++, GPL-3.0, mature)
- **[Return to the Roots](return_to_the_roots.md)** (C++, GPL-3.0, mature)
- **[Rigs of Rods](rigs_of_rods.md)** (C, C++, AngelScript, GPL-3.0, mature)
- **[Rocks'n'Diamonds](rocksndiamonds.md)** (C, GPL-2.0, mature)
- **[Rogue Clone IV](rogue_clone_iv.md)** (C, 3-clause BSD, mature, inactive since 2006)
- **[Roguish](roguish.md)** (JavaScript, 3-clause BSD, beta, inactive since 2015)
- **[Rolemaster Office](rolemaster_office.md)** (Java, Apache-2.0, mature)
- **[Rolisteam](rolisteam.md)** (C++, JavaScript, GPL-2.0, mature)
- **[Room for Change](room_for_change.md)** (Java, Apache-2.0, mature, inactive since 2013)
- **[RPDungeon - computer aided role playing](rpdungeon-computer_aided_role_playing.md)** (Pascal, GPL-2.0, beta, inactive since 2006)
- **[rpge](rpge.md)** (C, GPL-3.0, beta, inactive since 2014)
- **[Ryzom Core](ryzom_core.md)** (C++, AGPL-3.0, mature)
- **[S.C.O.U.R.G.E.](scourge.md)** (C++, GPL-2.0, beta, inactive since 2008)
- **[sandbox Game Maker](sandbox_game_maker.md)** (C++, C, Custom, mature, inactive since 2014)
- **[Scorched Moon](scorched_moon.md)** (Python, GPL-3.0, beta)
- **[Scorched3D](scorched3d.md)** (C++, GPL-2.0, mature, inactive since 2014)
- **[Scrabble3D](scrabble3d.md)** (Pascal, GPL-3.0, mature, inactive since 2015)
- **[Scrolling Game Development Kit 2](scrolling_game_development_kit_2.md)** (C#, GPL-2.0, mature, inactive since 2017)
- **[ScummVM](scummvm.md)** (C++, GPL-2.0, mature)
- **[SDL Asylum](sdl_asylum.md)** (C, GPL-3.0, mature, inactive since 2009)
- **[SDL Game Engine 2D](sdl_game_engine_2d.md)** (C, MIT, beta, inactive since 2014)
- **[SDL Sopwith](sdl_sopwith.md)** (C, GPL-2.0, mature, inactive since 2014)
- **[Secret Maryo Chronicles](secret_maryo_chronicles.md)** (C++, GPL-3.0, mature, inactive since 2009)
- **[Sengoku: Warring States of Japan](sengoku_warring_states_of_japan.md)** (C++, Lua, MIT, beta, inactive since 2008)
- **[Sentient Storage](sentient_storage.md)** (Python, Public domain, mature)
- **[Settlers III remake](settlers_iii_remake.md)** (Java, MIT, beta)
- **[Seven Kingdoms: Ancient Adversaries](seven_kingdoms_ancient_adversaries.md)** (C++, GPL-2.0, mature)
- **[SharpKonquest](sharpkonquest.md)** (C#, GPL-2.0, mature, inactive since 2007)
- **[SilverTree](silvertree.md)** (C++, GPL-3.0, beta, inactive since 2007)
- **[Simple and Fast Multimedia Library](simple_and_fast_multimedia_library.md)** (C++, zlib, mature)
- **[Simple DirectMedia Layer](simple_directmedia_layer.md)** (C, zlib, mature)
- **[Simple-Solitaire](simple-solitaire.md)** (Java, GPL-3.0, mature)
- **[Simutrans](simutrans.md)** (C++, Artistic License, mature)
- **[Sintel The Game](sintel_the_game.md)** (Python, MIT, beta, inactive since 2014)
- **[Skrupel - Tribute Compilation](skrupel-tribute_compilation.md)** (PHP, JavaScript, GPL-2.0, mature, inactive since 2011)
- **[SLASH'EM](slashem.md)** (C, Custom, beta, inactive since 2007)
- **[Slay](slay.md)** (Java, GPL-3.0, beta, inactive since 2010)
- **[Smash Battle](smash_battle.md)** (C++, ?, beta, inactive since 2011)
- **[Smash](smash.md)** (JavaScript, MIT, mature)
- **[SoftPixel Engine](softpixel_engine.md)** (C++, zlib, mature, inactive since 2013)
- **[Solarus](solarus.md)** (C, C++, Lua, GPL-3.0, mature)
- **[Song of Albion](song_of_albion.md)** (C, C++, Apache-2.0, mature, inactive since 2011)
- **[Source of Tales](source_of_tales.md)** (Lua, GPL-3.0, mature, inactive since 2013)
- **[Space Faring](space_faring.md)** (Java, GPL-3.0, beta)
- **[Space Opera](space_opera.md)** (Java, GPL-2.0, beta, inactive since 2008)
- **[Space Station 13](space_station_13.md)** (DM, AGPL-3.0, mature)
- **[Space Trader for Windows](space_trader_for_windows.md)** (C#, GPL-2.0, mature, inactive since 2009)
- **[Space War](space_war.md)** (Java, Apache-2.0, mature)
- **[SpaceTrader for Java](spacetrader_for_java.md)** (Java, GPL-2.0, mature, inactive since 2010)
- **[SpaceZero](spacezero.md)** (C, GPL-3.0, beta)
- **[Speed Dreams](speed_dreams.md)** (C++, GPL-2.0, mature)
- **[Spice Trade](spice_trade.md)** (Java, LGPL-2.0, mature, inactive since 2005)
- **[Spring RTS engine](spring_rts_engine.md)** (C++, C, Lua, GPL-2.0, mature)
- **[Star Control II: The Ur-Quan Masters](star_control_ii_the_ur-quan_masters.md)** (C, GPL-2.0, mature, inactive since 2011)
- **[Star Maiden Astraea Rio](star_maiden_astraea_rio.md)** (Ren'py, CC-BY-NC, mature)
- **[Star Ruler 2](star_ruler_2.md)** (C, C++, MIT, mature)
- **[StarBlastrix](starblastrix.md)** (C++, GPL-2.0, beta, inactive since 2006)
- **[Stareater](stareater.md)** (C#, GPL-3.0, beta)
- **[Stars! Nova](stars_nova.md)** (C#, GPL-2.0, beta)
- **[Stendhal](stendhal.md)** (Java, GPL-2.0, mature)
- **[StepMania](stepmania.md)** (C, C++, Lua, MIT, mature)
- **[Story of a Lost Sky](story_of_a_lost_sky.md)** (Python, 3-clause BSD, mature)
- **[Stunt Rally](stunt_rally.md)** (C, C++, GPL-3.0, mature)
- **[Summoning Wars](summoning_wars.md)** (C, C++, Lua, GPL-3.0, beta, inactive since 2014)
- **[Superpowers](superpowers.md)** (TypeScript, ISC, mature)
- **[SuperTuxKart](supertuxkart.md)** (C++, C, GPL-3.0, mature)
- **[Supremacy](supremacy.md)** (C#, Ms-RL, beta, inactive since 2014)
- **[SWIG](swig.md)** (C++, SWIG license, mature)
- **[T-Bots](t-bots.md)** (C, GPL-2.0, beta, inactive since 2004)
- **[Tales of Maj'Eyal](tales_of_majeyal.md)** (C, Lua, GPL-3.0, mature)
- **[Tanks of Freedom](tanks_of_freedom.md)** (GDScript, MIT, mature)
- **[Tenes Empanadas Graciela](tenes_empanadas_graciela.md)** (C, JavaScript, Perl, GPL-2.0, beta, inactive since 2015)
- **[Terasology](terasology.md)** (Java, Apache-2.0, mature)
- **[TetraVex](tetravex.md)** (Swift, GPL-3.0, beta)
- **[The Battle for Wesnoth](the_battle_for_wesnoth.md)** (C, C++, Java, Python, Lua, GPL-2.0, mature)
- **[The Bub's Brothers](the_bubs_brothers.md)** (Python, MIT, mature, inactive since 2013)
- **[The Butterfly Effect](the_butterfly_effect.md)** (C++, GPL-2.0, beta)
- **[The Castles of Dr. Creep](the_castles_of_dr_creep.md)** (C++, Shell, GPL-3.0, mature)
- **[The Clans](the_clans.md)** (C, GPL-2.0, beta, inactive since 2003)
- **[The Dark Mod](the_dark_mod.md)** (C++, GPL-3.0, mature)
- **[The Endless Dungeons](the_endless_dungeons.md)** (C, CC-BY-NC-SA-2.0, mature, inactive since 2015)
- **[The Epic of Heroes](the_epic_of_heroes.md)** (C++, GPL-3.0, beta, inactive since 2015)
- **[The hunt for the lost rainbow jewels (Jewelhunt)](the_hunt_for_the_lost_rainbow_jewels_jewelhunt.md)** (Java, GPL-2.0, beta)
- **[The Legend of Edgar](the_legend_of_edgar.md)** (C, GPL-2.0, mature)
- **[The Mana World](the_mana_world.md)** (PHP, GPL-2.0, mature)
- **[Thousand Parsec](thousand_parsec.md)** (C++, Python, GPL-2.0, beta, inactive since 2012)
- **[TinTin++](tintin.md)** (C, GPL-3.0, mature)
- **[TORCS, The Open Racing Car Simulator](torcs_the_open_racing_car_simulator.md)** (C++, GPL-2.0, mature, inactive since 2016)
- **[Tremulous](tremulous.md)** (C, GPL-2.0, mature, inactive since 2016)
- **[Tressette](tressette.md)** (C++, GPL-2.0, mature, inactive since 2017)
- **[Trinity Reign](trinity_reign.md)** (C++, GPL-3.0, beta, inactive since 2013)
- **[TripleA](triplea.md)** (Java, GPL-2.0, mature)
- **[TROPHY](trophy.md)** (C++, GPL-2.0, mature, inactive since 2012)
- **[Tumiki Fighters](tumiki_fighters.md)** (D, C++, 2-clause BSD, mature, inactive since 2005)
- **[Turious](turious.md)** (C, GPL-3.0, beta, inactive since 2014)
- **[Turn of War](turn_of_war.md)** (Java, GPL-3.0, beta, inactive since 2014)
- **[Tux Football](tux_football.md)** (C++, GPL-2.0, beta, inactive since 2012)
- **[Tux of Math Command](tux_of_math_command.md)** (C, GPL-3.0, mature, inactive since 2011)
- **[Tux Racer](tux_racer.md)** (C, GPL-2.0, beta, inactive since 2001)
- **[Tuxemon](tuxemon.md)** (Python, GPL-3.0, mature)
- **[TVTower](tvtower.md)** (BlitzMax, Lua, Custom, mature)
- **[TwinEngine](twinengine.md)** (C, GPL-2.0, mature, inactive since 2015)
- **[UFO2000](ufo2000.md)** (C, C++, Lua, GPL-2.0, mature, inactive since 2012)
- **[UFO: Alien Invasion](ufo_alien_invasion.md)** (C, C++, GPL-2.0, mature)
- **[UlDunAd](uldunad.md)** (Python, GPL-3.0, beta, inactive since 2011)
- **[UltraStar Deluxe](ultrastar_deluxe.md)** (Pascal, GPL-2.0, mature)
- **[UltraStar](ultrastar.md)** (Pascal, ?, mature, inactive since 2010)
- **[Umbra](umbra.md)** (Python, Custom, beta, inactive since 2002)
- **[Underworld Adventures](underworld_adventures.md)** (C++, Lua, GPL-2.0, beta, inactive since 2007)
- **[Unknown Horizons](unknown_horizons.md)** (Python, GPL-2.0, beta)
- **[UnNetHack](unnethack.md)** (C, Custom, mature)
- **[Unvanquished](unvanquished.md)** (C, C++, GPL-3.0, mature)
- **[Urho3D](urho3d.md)** (C++, AngelScript, MIT, mature)
- **[Valyria Tear](valyria_tear.md)** (Lua, C++, C, GPL-2.0, mature)
- **[VASSAL Engine](vassal_engine.md)** (Java, LGPL-2.1, mature)
- **[VCMI Project](vcmi_project.md)** (C++, GPL-2.0, mature)
- **[VDrift](vdrift.md)** (C++, GPL-3.0, mature, inactive since 2014)
- **[Vega Strike](vega_strike.md)** (C++, GPL-2.0, mature)
- **[Veloren](veloren.md)** (Rust, GPL-3.0, beta)
- **[War Of Kingdom](war_of_kingdom.md)** (C, C++, GPL-2.0, beta)
- **[Wargamer](wargamer.md)** (C++, GPL-2.0, mature, inactive since 2003)
- **[Wargus](wargus.md)** (C++, Lua, GPL-2.0, mature)
- **[Warzone 2100](warzone_2100.md)** (C++, GPL-2.0, mature)
- **[Waste's Edge](wastes_edge.md)** (Python, GPL-2.0, beta)
- **[WAtomic](watomic.md)** (Pascal, GPL-2.0, mature, inactive since 2005)
- **[Widelands](widelands.md)** (C, C++, Lua, Python, GPL-2.0, mature)
- **[Witch Blast](witch_blast.md)** (C++, GPL-3.0, beta, inactive since 2015)
- **[Wizards Magic](wizards_magic.md)** (Python, GPL-2.0, mature, inactive since 2012)
- **[Wolfpack Empire](wolfpack_empire.md)** (C, GPL-3.0, mature)
- **[World Builder](world_builder.md)** (Visual Basic, GPL-2.0, mature, inactive since 2007)
- **[World of Heroes](world_of_heroes.md)** (Python, 3-clause BSD, beta, inactive since 2009)
- **[World of Phaos](world_of_phaos.md)** (PHP, GPL-2.0, mature, inactive since 2011)
- **[WorldForge](worldforge.md)** (C++, GPL-2.0, mature)
- **[wxWidgets](wxwidgets.md)** (C++, Objective-C, Custom, mature)
- **[Wyrmsun](wyrmsun.md)** (Lua, C++, GPL-2.0, mature)
- **[X-Force: Fight For Destiny](x-force_fight_for_destiny.md)** (Pascal, GPL-2.0, beta, inactive since 2011)
- **[X-Moto](x-moto.md)** (C++, GPL-2.0, mature, inactive since 2014)
- **[XArchon](xarchon.md)** (C, C++, GPL-2.0, beta, inactive since 2003)
- **[Xconq](xconq.md)** (C++, GPL-2.0, mature, inactive since 2005)
- **[xdigger](xdigger.md)** (C, GPL-2.0, mature, inactive since 1999)
- **[Xenowar](xenowar.md)** (C, C++, GPL-3.0, mature, inactive since 2014)
- **[Xonotic](xonotic.md)** (C, GPL-3.0, mature)
- **[xoreos](xoreos.md)** (C++, GPL-3.0, beta)
- **[XPilot](xpilot.md)** (C, GPL-2.0, mature, inactive since 2010)
- **[XSera](xsera.md)** (C, Lua, MIT, beta, inactive since 2010)
- **[xu4](xu4.md)** (C++, GPL-2.0, mature, inactive since 2016)
- **[XZ Utils](xz_utils.md)** (C, Custom, mature)
- **[yaml-cpp](yaml-cpp.md)** (C++, MIT, mature)
- **[Yo Frankie!](yo_frankie.md)** (Blender Script, ?, mature, inactive since 2009)
- **[YSoccer](ysoccer.md)** (Java, GPL-2.0, mature)
- **[ZAngband](zangband.md)** (C, Custom, mature, inactive since 2005)
- **[Zelda: Mystery of Solarus DX](zelda_mystery_of_solarus_dx.md)** (Lua, GPL-3.0, mature)
- **[Zero Ballistics](zero_ballistics.md)** (C++, MIT, mature, inactive since 2013)
- **[Zero-K](zero-k.md)** (Lua, GPL-2.0, mature)
- **[Zetawar](zetawar.md)** (Clojure, MIT, mature)
- **[ZGameEditor](zgameeditor.md)** (Pascal, MIT, mature)
- **[zlib](zlib.md)** (C, zlib, mature)
- **[Zone of Control](zone_of_control.md)** (Rust, Apache-2.0, beta, inactive since 2017)