- A-Mazing Urho (C++, GPL-3.0, beta)
- Abuse (C++, Lisp, Public domain, GPL-2.0, WTFPL, mature, inactive since 2011)
- ACM (C, GPL-2.0, mature, inactive since 2000)
- AdaDoom3 (Ada, GPL-3.0, beta)
- Adanaxis (C++, GPL-2.0, mature, inactive since 2007)
- Afternoon Stalker (C++, GPL-2.0, mature, inactive since 2012)
- Ajax3d (JavaScript, GPL-2.0, beta, inactive since 2007)
- Aleph One (C++, Lua, GPL-3.0, mature)
- Amnesia: A Machine for Pigs (C++, GPL-3.0, mature, inactive since 2016)
- Amnesia: The Dark Descent (C++, GPL-3.0, mature, inactive since 2010)
- Anarch (C, C++, CC0, mature)
- Annex: Conquer the World (Lua, GPL-3.0, mature, inactive since 2014)
- Ardentryst (Python, GPL-3.0, mature, inactive since 2009)
- Ares Dogfighter (Java, GPL-3.0, beta, inactive since 2016)
- Armagetron Advanced (C++, GPL-2.0, mature)
- Armor Alley (JavaScript, CC-BY-NC-3.0, beta)
- Artillery Duel Reloaded (Python, GPL-3.0, beta, inactive since 2012)
- asdf (JavaScript, MIT, mature)
- AssaultCube (C, C++, Custom, mature, inactive since 2018)
- AstroMenace (C++, C, GPL-3.0, mature)
- ativayeban (C, C++, GPL-2.0, mature, inactive since 2015)
- Atomic Tanks (C++, C, GPL-2.0, mature, inactive since 2016)
- Awkaster (AWK, MIT, mature, inactive since 2017)
- Azimuth (C, GPL-3.0, mature)
- Ball and Paddle (C++, Scheme, Script, GPL-3.0, beta, inactive since 2009)
- Ball And Wall (JavaScript, MIT, mature, inactive since 2015)
- Ballerburg SDL (C, GPL-3.0, mature)
- Barbarian (Basic, ?, mature, inactive since 2014)
- Batrachians (C++, GPL-2.0, beta, inactive since 2012)
- Battle City (C, C++, Pascal, GPL-3.0, mature, inactive since 2013)
- Battle Tanks (C++, GPL-2.0, mature, inactive since 2009)
- Beat Harvester (Python, GPL-2.0, beta, inactive since 2009)
- Berusky II (C++, GPL-3.0, beta)
- Berusky (C++, GPL-3.0, mature)
- Biniax (C, zlib, mature, inactive since 2012)
- Bitfighter (C, C++, GPL-2.0, mature)
- BlakedAwesomenaughts (JavaScript, PHP, MIT, beta, inactive since 2015)
- Blasphemer (None, Python, None, mature, inactive since 2017)
- Blobby Volley 2 (C++, GPL-2.0, mature)
- Bloboats (C++, GPL-2.0, mature, inactive since 2006)
- Bloodworks (C, C++, C#, GPL-3.0, mature, inactive since 2018)
- Blue Nebula (C, C++, zlib, mature)
- Blutfest (GDScript, GPL-3.0, mature)
- Bombermaaan (C++, GPL-3.0, mature, inactive since 2010)
- Bombic2 (C++, GPL-2.0, beta, inactive since 2010)
- Bombic (C++, Objective-C, GPL-2.0, beta, inactive since 2005)
- Bombman (Python, CC0, mature)
- BOOM: Remake (C++, Custom, mature)
- Boulder Dash (Java, MIT, mature, inactive since 2015)
- bratwurst (Lisp, GPL-2.0, mature, inactive since 2009)
- Breakout-VR (C#, MIT, beta, inactive since 2017)
- British Bingo (JavaScript, GPL-3.0, mature)
- buggyGame (Python, GPL-2.0, beta, inactive since 2007)
- Build engine (C, C++, Custom, mature)
- BurgerSpace (C++, GPL-2.0, mature, inactive since 2013)
- BZFlag (C++, LGPL-2.1, MPL-2.0, mature)
- C-Dogs SDL (C, GPL-2.0, mature)
- Cabbages and Kings (Python, MIT, mature)
- Cadaver (C++, GPL-2.0, beta, inactive since 2009)
- Cannonball (C++, MAME, beta)
- Captain Blood (C++, C, GPL-3.0, mature)
- Carnage3D (C++, C, MIT, beta)
- Cat Mother Dead Justice (C++, 3-clause BSD, GPL-2.0, beta, inactive since 2003)
- Catacomb 3-D (C, C++, GPL-2.0, mature, inactive since 1991)
- Catacomb (Pascal, GPL-2.0, mature, inactive since 1989)
- Cattle Bity (TypeScript, MIT, mature)
- CavePacker (JavaScript, C, C++, Lua, GPL-3.0, mature)
- CAVEZ of PHEAR (C, GPL-3.0, beta)
- cc94 (C++, Python, AGPL-3.0, beta)
- Celestron (Python, GPL-3.0, beta, inactive since 2012)
- Chocolate Doom (C, GPL-2.0, mature)
- Chocolate Duke3D (C, GPL-2.0, Custom, beta, inactive since 2016)
- Chromium B.S.U. (C++, Artistic License-1.0, mature)
- Circus Linux! (C, GPL-2.0, mature, inactive since 2000)
- Classic RBDoom 3 BFG (C, C++, GPL-3.0, mature)
- Clonepoint (C++, GPL-3.0, beta)
- CnC Remastered Collection (C++, C#, GPL-3.0, mature, inactive since 2020)
- Combat Simulator Project (C++, GPL-2.0, beta, inactive since 2010)
- Commander Genius (C, C++, GPL-2.0, mature)
- CommandoJS (JavaScript, CoffeeScript, MIT, beta, inactive since 2012)
- Cortex Command - open source (C, C++, AGPL-3.0, mature)
- Cortex Command Community Project (C++, C, Lua, AGPL-3.0, mature)
- Cosmosmash (C++, GPL-2.0, mature, inactive since 2013)
- Crazy Cars (Basic, ?, mature, inactive since 2014)
- Creep Smash (Java, GPL-3.0, beta, inactive since 2011)
- CroftEngine (C++, Python, LGPL-3.0, beta)
- Cross The Road (Elm, JavaScript, AGPL-3.0, mature)
- Cube 2: Sauerbraten (C, C++, Custom, mature, inactive since 2020)
- Cube (C, C++, Custom, mature, inactive since 2005)
- Der Clou! (C, Custom, beta, inactive since 2017)
- Descent 3 (C++, C, GPL-3.0, mature)
- Devilution (C, C++, Unlicense, mature)
- DevilutionX (C, C++, Unlicense, mature)
- DGEngine (C++, zlib, GPL-3.0, beta)
- dhewm3 (C, C++, GPL-3.0, mature)
- Digger Remastered (C, GPL-2.0, mature, inactive since 2004)
- donut (C, C++, GPL-3.0, beta)
- Doom Legacy (C++, GPL-2.0, mature)
- DOOM Retro (C, C++, GPL-3.0, mature)
- DOOM-iOS (C++, C, GPL-2.0, mature, inactive since 2012)
- Doom64EX (C, C++, GPL-2.0, mature)
- DOOM (C, C++, Custom, mature, inactive since 2012)
- Doomsday Engine (C, C++, GPL-2.0, GPL-3.0, LGPL-3.0, mature)
- dRally (Assembly, C, MIT, beta)
- DUGA (Python, MPL-2.0, beta, inactive since 2018)
- Duke 2 Reconstructed (C, GPL-2.0, mature)
- Duke3D (C, GPL-2.0, beta, inactive since 2009)
- Duke3d_w32 (C, GPL-2.0, beta, inactive since 2008)
- DukeGDX (Java, GPL-3.0, beta)
- Dungeon Monkey Unlimited (Pascal, LGPL-2.1, mature, inactive since 2010)
- Dungeon of Quake (Odin, Pascal, MIT, Unlicense, beta)
- DynaDungeons (GDScript, GPL-3.0, beta, inactive since 2018)
- EDGE (C++, C, GPL-2.0, mature)
- EDuke32 (C, C++, GPL-2.0, mature)
- Elite remake (C, 3-clause BSD, mature, inactive since 2008)
- Empty Clip (C++, GPL-2.0, mature)
- Epiar (C, C++, Lua, GPL-2.0, beta)
- ET: Legacy (C, C++, Lua, GPL-3.0, mature)
- Excellent Bifurcation (C, GPL-2.0, mature, inactive since 2007)
- ezQuake (C, C++, GPL-2.0, mature)
- Fanwor (C, GPL-2.0, mature)
- Fire Madness (Pascal, GPL-3.0, mature, inactive since 2016)
- Fire Strike Retro (Java, Haxe, JavaScript, Ruby, PHP, MIT, mature)
- Fitzquake (C, GPL-2.0, beta, inactive since 2009)
- Flare (C++, Java, Python, GPL-3.0, mature)
- Flukz (C++, GPL-2.0, beta, inactive since 2014)
- Foxy Misfortunes (Pascal, GPL-3.0, mature)
- FQuake3 (F#, C, GPL-2.0, beta, inactive since 2014)
- fRaBs (Lisp, C++, C, Public domain, mature, inactive since 2016)
- freeablo (C++, GPL-3.0, beta)
- FreeCS (QuakeC, GPL-2.0, mature)
- Freedoom (None, Python, None, beta)
- FreePrince (C, GPL-2.0, beta, inactive since 2011)
- FTE QuakeWorld (C, GPL-2.0, mature)
- FTEQW (C, GPL-2.0, mature)
- Future Cop: MIT (C++, C, MIT, beta)
- Galaxy Forces V2 (C++, Public domain, mature)
- Gang Garrison 2 (Game Maker Script, MPL-2.0, mature)
- GDash (C++, MIT, beta)
- GDHexGrid (GDScript, MIT, mature)
- Ghostly (C++, GPL-3.0, mature, inactive since 2016)
- GL TRON (Java, GPL-3.0, mature, inactive since 2012)
- GL-117 (C++, GPL-2.0, mature, inactive since 2005)
- Gloomy Dungeons 2 (Java, MIT, mature)
- Gloomy Dungeons (Java, MIT, mature, inactive since 2018)
- GLtron (C, ?, beta, inactive since 2017)
- GoldenEye: Source (C++, C, GPL-3.0, mature, inactive since 2018)
- GPL Arcade Volleyball (C++, GPL-2.0, beta, inactive since 2006)
- Granatier (C++, GPL-2.0, mature)
- Grimsonland (JavaScript, TypeScript, MIT, mature, inactive since 2017)
- GUSANOS (C++, GPL-2.0, beta, inactive since 2006)
- Gusty's Serpents (C++, GPL-3.0, beta, inactive since 2014)
- GZDoom (C, C++, GPL-3.0, mature)
- Hammer of Thyrion (C, GPL-2.0, mature)
- Head over Heels (C++, GPL-3.0, mature)
- Hedgewars (Lua, C, C++, Pascal, Haskell, GPL-2.0, mature)
- Helion (C#, GPL-3.0, mature)
- Help Hannah's Horse (C++, GPL-2.0, beta, inactive since 2008)
- heXon (C++, GPL-2.0, beta)
- Hexoshi (Python, GPL-3.0, beta, inactive since 2016)
- HolySpirit (C++, Haskell, GPL-3.0, beta, inactive since 2013)
- Hovertank 3D (C++, Assembly, GPL-2.0, mature, inactive since 2014)
- Hypersomnia (C++, AGPL-3.0, mature)
- iiChantra (C++, MIT, beta, inactive since 2012)
- IMaze (C, 4-clause BSD, mature, inactive since 2001)
- ioquake3 (C, GPL-2.0, mature)
- Jake2 (Java, GPL-2.0, beta, inactive since 2006)
- JediAcademyLinux (C++, GPL-2.0, beta, inactive since 2017)
- Jet-Story (Assembly, C, C++, MIT, beta)
- Kartering (C, GPL-2.0, MIT, ISC, beta, inactive since 2015)
- Key Runner (C++, Script, GPL-3.0, mature, inactive since 2013)
- KGoldrunner (C++, GPL-2.0, mature)
- Kobo Deluxe (C++, GPL-2.0, beta, inactive since 2007)
- KRaptor (C, MIT, beta, inactive since 2004)
- LAB3D/SDL (ktpanda) (C, Custom, mature, inactive since 2015)
- LAB3D/SDL (C, Custom, mature, inactive since 2013)
- LastTry (Java, MIT, beta, inactive since 2017)
- LGames (C++, GPL-2.0, mature)
- Liblast (GDScript, AGPL-3.0, beta)
- Librelancer (C, C#, MIT, beta)
- LibreQuake (Python, 3-clause BSD, beta)
- LieroLibre (C++, 2-clause BSD, mature, inactive since 2017)
- Linwarrior 3D (C++, Apache-2.0, mature, inactive since 2010)
- LionEngine (Java, GPL-3.0, mature)
- Liquid War (C, Script, GPL-3.0, mature, inactive since 2015)
- Lugaru HD (C++, GPL-2.0, mature)
- LZWolf (C++, 3-clause BSD, mature)
- Maelstrom (C, C++, GPL-2.0, mature, inactive since 2002)
- MafiaUnity (C#, Apache-2.0, beta, inactive since 2020)
- MechCommander 2 Omnitech (C++, MS-PL, beta, inactive since 2013)
- Mega Mario (C++, LGPL-2.1, mature, inactive since 2012)
- MicroWar 2.0 (Python, 3-clause BSD, mature, inactive since 2009)
- Mindustry (Java, GPL-3.0, mature)
- Mininim (C, GPL-3.0, beta, inactive since 2017)
- mk.js (JavaScript, MIT, beta)
- Mojotron: Robot Wars (C++, GPL-2.0, mature, inactive since 2019)
- Moon-buggy (C, GPL-2.0, mature, inactive since 2006)
- Mr.Boom (C++, C, MIT, mature)
- Mtp Target (C++, GPL-2.0, mature, inactive since 2008)
- Nanosaur II: Hatchling (C, C++, CC-BY-NC-SA-4.0, mature)
- Nanosaur (C, CC-BY-NC-SA-4.0, mature)
- NEO-RAW (C++, GPL-2.0, mature, inactive since 2020)
- Netrek (C, Custom, mature, inactive since 2009)
- Neverball (C, C++, GPL-2.0, mature)
- Nexuiz (C++, GPL-2.0, mature)
- noiz2-droid (Java, 2-clause BSD, mature, inactive since 2015)
- Not Pacman (Lua, WTFPL, mature, inactive since 2013)
- Nuncabola (Java, GPL-2.0, beta)
- nXtank (Python, C++, GPL-3.0, beta, inactive since 2010)
- Ogrian Carpet (C++, MIT, beta, inactive since 2018)
- Open Saucer (C++, GPL-2.0, beta)
- Open Surge (C, GPL-3.0, beta)
- Open Zelda (C, C++, zlib, mature, inactive since 2015)
- OpenArena Engine (C, GPL-2.0, mature, inactive since 2012)
- OpenAWE (C++, GPL-3.0, beta)
- OpenBiohazard2 (Go, MIT, beta)
- OpenClonk (C, C++, ISC, mature)
- OpenD2 (C, C++, GPL-3.0, beta)
- openDarkEngine (C++, GPL-2.0, beta, inactive since 2018)
- OpenDiablo2 (Go, GPL-3.0, mature)
- OpenDrakan (C++, GPL-3.0, beta)
- OpenFire (C, MIT, beta, inactive since 2018)
- Openfrag (C++, Lua, GPL-2.0, beta, inactive since 2008)
- OpenGTA (C++, Custom, beta, inactive since 2007)
- OpenJK (C, C++, GPL-2.0, beta)
- OpenJKDF2 (C, ISC, beta)
- OpenLara (C++, C, 2-clause BSD, mature)
- OpenLiberty (GDScript, MIT, beta)
- OpenLiero (C++, C, Custom, mature, inactive since 2015)
- OpenLieroX (C++, LGPL-2.0, mature)
- OpenMoHAA (C, C++, GPL-2.0, beta)
- OpenMortal (C++, Perl, GPL-2.0, beta, inactive since 2006)
- openMSX (C++, GPL-2.0, mature)
- OpenNitemare3D (C#, GPL-3.0, beta, inactive since 2021)
- OpenNotrium (C++, GPL-3.0, beta)
- OpenNox (C, Go, GPL-3.0, mature)
- OpenOMF (C, C++, MIT, beta)
- OpenRaider (C, C++, GPL-2.0, beta, inactive since 2015)
- OpenRW (C, C++, GPL-3.0, beta)
- OpenTomb (C, C++, Lua, LGPL-3.0, beta)
- OpenTyrian2000 (C, GPL-2.0, mature)
- OpenTyrian (C, GPL-2.0, beta, inactive since 2018)
- OpenVice (C#, ?, beta, inactive since 2021)
- OpenXRay (C++, Lua, ?, mature)
- OpenYandere (C#, GPL-3.0, beta, inactive since 2018)
- Overgrowth (C, C++, Apache-2.0, mature)
- Pacewar (Python, GPL-3.0, mature, inactive since 2017)
- PainTown (C++, Java, Python, 3-clause BSD, mature)
- Pang Zero (Perl, GPL-2.0, beta, inactive since 2007)
- PCExhumed (C++, Custom, beta)
- Penumbra: Overture (C++, C, GPL-3.0, mature)
- Point & Hit (Java, GPL-3.0, mature, inactive since 2017)
- Potato Killer (Python, GPL-3.0, beta, inactive since 2011)
- PowerslaveGDX (Java, Custom, beta)
- Prince-Monogame (C#, GPL-2.0, beta)
- PsyDoom (C, C++, GPL-3.0, mature)
- Quake 2 (C, Assembly, GPL-2.0, mature)
- Quake II Rerelease (C, C++, GPL-2.0, mature)
- QuakeSpasm (C, GPL-2.0, mature)
- R.E.L.I.V.E. (C++, MIT, beta)
- Rabbit Escape (Java, GPL-2.0, mature)
- RAD (Pascal, C, GPL-2.0, mature)
- Raptor: Call of the Shadows (C, GPL-3.0, beta)
- RaumBaller (Java, GPL-3.0, mature)
- Raze (C++, GPL-2.0, mature)
- Red Eclipse (C++, C, zlib, mature)
- RedneckGDX (Java, Custom, beta)
- Rednukem (C++, Custom, beta)
- ReflectionHLE (C, Lua, GPL-2.0, mature)
- remc2 (C, GPL-3.0, mature)
- Rescue! Max (Java, GPL-3.0, beta, inactive since 2013)
- Return of Dr. Destructo (C++, MIT, mature, inactive since 2015)
- Rigel Engine (C++, GPL-2.0, beta)
- Rise of the Triad for Linux (C, GPL-2.0, mature, inactive since 2012)
- Robot Redemption (C++, CC-BY-NC-SA-4.0, GPL-2.0, mature, inactive since 2014)
- rock-raiders-remake (JavaScript, MIT, beta)
- Rocks'n'Diamonds (C, GPL-2.0, mature)
- Rott94 (C, C++, GPL-2.0, beta)
- rottexpr (C, GPL-2.0, beta)
- SDL Asylum (C, GPL-3.0, mature, inactive since 2009)
- SDL Bomber (C, GPL-2.0, mature, inactive since 2012)
- SDL Sopwith (C, C++, GPL-2.0, mature, inactive since 2014)
- SDLPoP (C, GPL-3.0, mature)
- Secret Maryo Chronicles (C++, GPL-3.0, mature, inactive since 2009)
- sensitive-js (JavaScript, Custom, beta, inactive since 2017)
- Serious Sam Classic: Vulkan (C, C++, GPL-2.0, mature)
- Serious Sam Classic (C++, GPL-2.0, mature)
- shadow-of-the-beast-html5 (JavaScript, Apache-2.0, beta, inactive since 2017)
- Sine (C, C++, MIT, beta)
- Slune (Python, GPL-2.0, mature, inactive since 2007)
- Smash Battle (C++, GPL-2.0, beta, inactive since 2011)
- Smash (JavaScript, MIT, mature)
- Solarus (C, C++, Lua, GPL-3.0, mature)
- SolarWolf (Python, LGPL-2.1, mature, inactive since 2004)
- Soldank (Rust, MIT, beta)
- Soldat (C, Pascal, MIT, mature)
- Sole Collector (Java, MIT, beta, inactive since 2018)
- Space Station 13 (DM, AGPL-3.0, GPL-3.0, mature)
- Space Station 3D (C#, MIT, beta)
- SpacePeng! (Java, GPL-3.0, mature, inactive since 2017)
- Speed Dreams (C++, GPL-2.0, mature)
- StarBlastrix (C++, GPL-2.0, beta, inactive since 2006)
- starshatter-open (C++, 3-clause BSD, beta, inactive since 2015)
- Starun (Java, GPL-3.0, mature, inactive since 2017)
- Stunt Rally (C, C++, GPL-3.0, mature)
- SunDog Resurrection (Java, Python, Artistic License-1.0, beta)
- SuperTuxKart (C++, C, GPL-3.0, mature)
- SuperTuxParty (GDScript, GPL-3.0, beta)
- SurrealEngine (C++, 3-clause BSD, beta)
- Syndicate Wars Port (C, GPL-3.0, beta, inactive since 2010)
- Taisei Project (C, Python, MIT, mature)
- Tank: Zone of Death (C++, Lua, GPL-3.0, beta, inactive since 2017)
- TankistOnline (Python, GPL-3.0, beta)
- Team Tactics (Java, MIT, beta, inactive since 2016)
- TekwarGDX (Java, Custom, beta)
- Terminal Overload (C++, C, C#, GPL-3.0, beta, inactive since 2016)
- terrarium (C++, Script, GPL-2.0, beta)
- The Catacomb (C, C++, GPL-2.0, mature, inactive since 1990)
- The Force Engine (C++, GPL-2.0, beta)
- The Legend of Edgar (C, GPL-2.0, mature)
- Thugaim (Java, MIT, mature, inactive since 2017)
- Toppler (C++, GPL-2.0, mature, inactive since 2012)
- Torso Ninja 2 (Python, GPL-3.0, mature, inactive since 2017)
- Torso Ninja (Python, GPL-3.0, mature, inactive since 2017)
- TOSIOS (TypeScript, MIT, beta)
- Tremulous (C, GPL-2.0, mature, inactive since 2016)
- Tressette (C++, GPL-2.0, mature, inactive since 2017)
- Trigger Rally (JavaScript, GPL-3.0, beta)
- TUSSLE (Python, GPL-3.0, mature, inactive since 2017)
- Tux Racer (C, C++, GPL-2.0, beta, inactive since 2001)
- Tux! (C++, GPL-3.0, beta)
- Tyrian Remake (Java, GPL-2.0, beta)
- Uebergame (TorqueScript, C#, MIT, mature)
- Unvanquished (C, C++, GPL-3.0, mature)
- UTEngine (C++, zlib, beta)
- Virus Attack (Java, AGPL-3.0, mature)
- Vorton (C, GPL-3.0, beta, inactive since 2004)
- War Thunder (C++, C, 3-clause BSD, mature)
- WebQuake (JavaScript, GPL-2.0, mature, inactive since 2019)
- WitchavenGDX (Java, Custom, beta)
- Wolf3dX (C#, GPL-2.0, beta)
- Wolf4SDL (C, GPL-2.0, mature)
- Word War vi (C, GPL-2.0, mature)
- X-Moto (C++, GPL-2.0, mature, inactive since 2014)
- xdigger (C, GPL-2.0, mature, inactive since 1999)
- xGreed (Pascal, Custom, beta)
- XL Engine (C++, MIT, beta, inactive since 2018)
- Xonotic (C, C++, Java, Perl, GPL-3.0, mature)
- XPilot NG (C, GPL-2.0, mature, inactive since 2010)
- XPilot (C, C++, GPL-2.0, mature, inactive since 2010)
- Yamagi Quake II (C, GPL-2.0, mature)
- Yet Another Doom Clone (JavaScript, Python, GPL-3.0, mature)
- Yo Frankie! (Blender Script, ?, mature, inactive since 2009)
- Zandronum (C, Custom, mature, inactive since 2017)
- Zatacka X (C, GPL-3.0, beta)
- Zauberer (None, ISC, beta, inactive since 2018)
- ZEQ2 Lite (Script, ?, beta)
- Zero Ballistics (C++, MIT, mature, inactive since 2013)