Open-source video game

Many Linux distributions require for inclusion that the game content is freely redistributable, freeware or commercial restriction clauses are prohibited.

[3] In the 1990s a challenge to build high-quality content for games was the missing availability or the excessive price for tools like 3D modeller or toolsets for level design.

[22][23] Still developed and played today, front-ends for frameworks such as X11, SDL, GTK and Qt, plus fuller featured variants such as Iso-Angband, glHack and Vulture's Eye have kept the games accessible.

[29] These included XAsteroids, XBattle, XBoing, X-Bomber, XConq, XDigger, XEmeraldia, XGalaga, XGammon, XLander, XLife, XMahjong, XMine, XSoldier, XPilot, XRobots, XRubiks, XShogi, XScavenger, XTris, XTron, and XTic.

The GNU Image Manipulation Program, MyPaint, Krita, Inkscape, Synfig, Pencil2D, Audacity, Rosegarden, MidiEditor,[51] OpenShot, Kdenlive, Pitivi, Blender, MakeHuman, MM3D,[52][53] and other applications have provided an entire open source toolchain for creative projects.

Various free software emulators and compatibility layers have also been produced, such as MAME and MESS, Mednafen, higan, Executor, Darling, lxrun, Cygwin, Dosbox, ScummVM, Anbox, Wine and Proton, allowing games to run in new environments (broadly targeted by the RetroArch front-end).

[76] Engines even exist for high-level programming languages such as Python[77] (Pyglet, PyOpenGL,[78] Spineless,[79] Soya3D, PyUnity,[80] PyZOE[81]), Pascal (GLScene, Castle,[82] nxPascal,[83] ZenGL[84]), Lua (LÖVR,[85] LÖVE3D[86]), Rust (Amethyst,[87] Bevy,[88] Fyrox,[89] Piston[90]), Zig (Mach[91]), Java[92] (libGDX, Jake2, jMonkeyEngine,[93] Env3D[94]), Kotlin (KorGE,[95] MiniGDX[96]), Go[97] (Azul3D,[98] G3N[99]), Ruby (Candy Gear[100]), Gambas (PS Tech[101]) FreeBASIC (OpenB3D[102]) in addition to ActionScript (Away3D), Haxe (Heaps.io,[103] Kha[104]) and JavaScript (Babylon.js, Three.js) using WebGL.

[130] These include Freedoom, Blasphemer, Open Quartz, LibreQuake, Nexuiz/Xonotic, Tremulous/Unvanquished, Quetoo,[131] and OpenArena on id Tech, plus Terminal Overload[132] and Uebergame[133] on Torque.

Freeware games, such as Harmony,[134] The Adventures of Square,[135] The Hunted Chronicle 2,[136] Force: Leashed,[137] Retro Blazer,[138] Alien Arena, World of Padman, and Urban Terror,[139] have also taken advantage of these free engines and sometimes have given code back to the community.

[48] Formerly proprietary games such as Jump 'n Bump, Dink Smallwood, Clonk, Seven Kingdoms, AstroMenace, Warzone 2100, Glitch, Maelstrom, Planet Blupi,[162] Avara, Eat the Whistle,[163] Blades of Exile, Star Control 2, SimCity, Fish Fillets, HoverRace, Duelyst, as well Abuse and the unfinished Golgotha have even been entirely released freely, including multimedia assets and levels.

[172] Source code releases were used however for unauthorized versions of Lugaru and Abuse that were allowed onto the App Store prior to takedown claims by the original developers.

Many of these are clones[190] such as Pingus, Lix,[191] and Rabbit Escape[192] (Lemmings), BomberClone (Atomic Bomberman),[193] Enigma (Oxyd), Beats of Rage (Streets of Rage), TetriNET (Tetris), GAV,[194] Blobby Volley, and SlimeVolley[195] (Arcade Volleyball), Ace of Penguins (Microsoft Solitaire),[196] Crack Attack (Tetris Attack),[197] Pang Zero[198] and PiX Pang[199] (Super Pang), System Syzygy (Systems' Twilight),[200] Troll Bridge, Fanwor: The Legend of Gemda[201] and ZQuest Classic[202] (The Legend of Zelda), Rocks'n'Diamonds and Epiphany[203] (Boulder Dash), Numpty Physics (Crayon Physics),[204] Pathological (Logical),[205] PainTown (MUGEN),[206] FloboPoyo,[207] GTK Puyo Puyo[208] (Puyo Puyo), Paranoid,[209] LBreakOut 2,[210] and Briquolo[211] (Breakout), BurgerSpace (BurgerTime),[212] Einstein Puzzle (Sherlock),[213] UltraStar (SingStar), OpenClonk (Clonk), FreeGish (Gish),[214] Hexoshi (Super Metroid),[215] I Have No Tomatoes[216] and Bombic[217] (Dynablaster), Scorched 3D and XScorch[218] (Scorched Earth), FreeVikings (The Lost Vikings),[219] Savage Wheels (Destruction Derby),[220] Penguin Command (Missile Command),[221] Sable (Space Harrier),[222] Circus Linux!

(Circus Atari),[223] Falling Time (Fall Down),[224] Toppler (Tower Toppler),[225][226] Gem Drop X (Gem Drop),[227] Fish Supper[228] and Froggix[229] (Frogger), OpenMortal (Mortal Kombat),[230][231] Triplane Turmoil and SDL Sopwth[232] (Sopwith), Taisei Project (Touhou Project),[233] Crown and Cutlass (Sid Meier's Pirates!

),[234] IceBreaker (JezzBall),[235] Monsterz (Bejeweled),[236] Tux Football[237] and YSoccer[238] (Sensible Soccer), iMaze (MIDI Maze),[239] PixBros (Bubble Bobble),[240] Surge the Rabbit (Sonic the Hedgehog),[241] Dave Gnukem (Duke Nukem),[242] Formido[243] (Phobia), Violetland[244] and Grimsonland[245] (Crimsonland), Luanti (Minecraft),[246] SolarWolf (Solar Fox),[247] Freedroid[248] and Nighthawk[249] (Paradroid), Tile World and Escape[250] (Chip's Challenge),[251] FreeOrion (Master of Orion),[252] Tuxánci (Bulánci), Super Tux Party (Mario Party),[253] Neverball (Super Monkey Ball),[254] Kraptor/RafKill (Raptor: Call of the Shadows), Trackballs (Marble Madness),[255] Hurrican (Turrican),[256] OpenTyrian (Tyrian),[257] HexGL (Wipeout),[258] Zaz (Zuma), Ostrich Riders (Joust),[259] Endless Sky[260] and Naev[261] (Escape Velocity), Pioneer and Oolite (Elite), SuperTux, Secret Maryo Chronicles and Mari0 (Super Mario Bros.),[262] SuperTux 3D[263] (Super Mario 64), WarMUX[264] and Hedgewars[265] (Worms), OpenLieroX, NiL,[266] LieroLibre (Liero) as well as Frets on Fire (Guitar Hero), and StepMania (Dance Dance Revolution).

Frozen Bubble, originally a clone of Puzzle Bobble, has become a classic known for its addictive gameplay and winner of many Linux Journal Reader's Choice Awards.

Rescue,[282] Nikwi,[283] Plee the Bear,[284] Super Bombinhas,[285] Stringrolled,[286] Teeworlds, Which Way Is Up,[287] and Worminator 3,[288][289] puzzle games such as Anagramarama,[290] Angry, Drunken, Dwarves,[291] Balls Blocks and Mazes,[292] Battery,[293] Brikx,[294] Chroma,[295] Dynamite,[296] Hex-a-Hop,[297] irrlamb,[298] kiki the nano bot, Krystal Drop,[299] Marble Muncher,[300] Memonix,[301] Minilens,[302] Raincat,[303] Tetzle,[304] The Powder Toy, Wizznic!,[305] and Xye,[306] arcade games such as Apricots,[307] Airstrike,[308] Avoision,[309] Battle Tanks,[310] Barrage,[311] C-Dogs, Chromium B.S.U., Emilia Pinball,[312] the Enemy Lines series,[313][314] FLAW,[315] Free Tennis,[316] the Geki series,[317] Hase,[318] Help Hannah's Horse,[319] Heroes,[320] Jammer the Gardener,[321] KETM,[322] Kuklomenos,[323] Librerama,[324] Luola,[325] M.A.R.S.,[326] Meat Fighter - The Weiner Warrior,[225] Hikou no mizu,[327] Moag,[328] OilWar,[329] osu!, Osgg,[330] Orbital Eunuchs Sniper,[331] Overgod,[332] Powermanga,[333][334] Ri-li,[335] Super Transball 2,[336] Technoball Z,[337] The Sheep Killer,[338] Variations on Rockdodger,[339] Warlock's Gauntlet,[340] and Zorn,[341] have been able to carve out their own niches.

Most prominently among Linux[344] users and other free Unix-like systems such as BSD,[345] Solaris,[346] Darwin,[347] ToaruOS,[348] Xv6,[349] Fiwix,[350] Redox,[351][352] and SerenityOS,[353] but also some Macintosh[354] players and even a few Microsoft Windows gamers as well as OpenHarmony embedded open source platform.

Additionally, these games provide options for a variety of alternative and hobbyist systems,[360] including CP/M,[361] OS/2,[362][363] BeOS,[364][365] RISC OS,[366][367][368] QNX,[369] IRIX,[370][371] MenuetOS,[372] Phantom OS,[373] Genode,[374] HelenOS,[375] SkyOS,[376] TempleOS,[377] SymbOS,[378][379] FreeRTOS,[380] AmigaOS[381][382] (plus WarpOS[383]), and MorphOS,[384] as well as later implementations such as FreeDOS,[385] ArcaOS,[386] ReactOS,[387] Haiku,[388][389] ZETA,[390] KolibriOS,[391] Syllable Desktop,[392] AmigaOS 4,[393] and AROS.

[394][395] Particularly prolific is New Breed Software, which offers games for all or most of those systems,[396] as well as for vintage computers such as the Atari 8-bit, Atari ST, and Amiga, homebrew for several video game consoles such as the Sega Dreamcast, Sony PlayStation 2 and Nintendo Wii, handhelds such as the Sony PSP, Nintendo DS and GP2X, as well as mobile platforms such as the Agenda VR3, OpenZaurus, Maemo, and Symbian OS.

[48][399] Xconq and XBattle, and later Freeciv and Lincity, began the trend, and were followed by other clone titles like FreeCol, UnCiv,[400] Crimson Fields,[401] C-evo, LordsAWar!, Freelords, Civil,[402] LGeneral,[403] Open General,[404] OpenPanzer,[405] OpenCity, OpenRTS,[406] TripleA,[407] Mars, Land of No Mercy,[408] Ophiuchus,[409] Mindustry,[410] Tanks of Freedom,[411] OpenRA, OpenRCT2, OpenTTD, Simutrans, StormWar,[412] Advanced Strategic Command,[413] Tenes Empanadas Graciela, Endgame: Singularity, Thousand Parsec, Unknown Horizons and Widelands.

[415] With the new, legally inoffensive name Stratagus and the old FreeCraft assets renamed Aleona's Tales, the team began work on a new strategy game called Bos Wars.

Other racing games include versions of Racer, VDrift, Rigs of Rods, Slune,[425] GLtron and Armagetron Advanced, YORG,[426] the Mario Kart–inspired SuperTuxKart, Elasto Mania clone X-Moto, SkyRoads imitator Orbit-Hopper,[427] sledding game Extreme Tux Racer, the text based ZRacer,[428] and the top-down Trophy,[429] Dust Racing 2D and Pixel Wheels.

Single-player role-playing games are also available, such as A Dark Room, Heroes of Allacrost,[434] Valyria Tear,[435] Empty Clip,[436] Summoning Wars,[437] GNU FreeDink,[438] FLARE,[439] Heroine Dusk,[440] FreedroidRPG,[441] the Cube World inspired Veloren,[442] and the Pokémon derived Tuxemon,[443] OPMon,[444] and Pigeon Ascent.

[5] Game jams such as Ludum Dare and Game Off are often run on open source principles, frequently using free frameworks such as pygame, Arcade,[446] Wasabi2D,[447] and Ren'Py for Python, Ruby2D[448] and Gosu[449] for Ruby, GGEZ[450] for Rust, LibGDX for Java, MiniGDX[96] for Kotlin, LÖVE and Solar2D for Lua, Ebitengine[451] for Go, Phaser, Panda,[452] and SuperPower for HTML5,[453] as well as nCine,[454] Solarus,[455] Starling, MonoGame, Twine, and Cocos2d.

[462] Popular games were generally separate efforts, except for instances of people working on them known for other projects such as Ingo Ruhnke (Pingus), Bill Kendrick (SuperTux) and Steve Baker (TuxKart).

The game's canon is maintained through review and discussion over which submitted campaigns become official, thus setting up a model for community input and organized results.

In addition, the project is worked on by many well-known free programmers, artists, designers and musicians such as the co-founder of the Open Source Initiative Eric S. Raymond,[490] and Linux kernel hacker Rusty Russell.

Some examples include the transformation of TuxKart into the more modern SuperTuxKart, work on Pingus and SuperTux, and Lincity-NG, an updated version of Lincity with superior graphics.

[499] Identical Software has also worked to modernize various libre games, including Ostrich Riders, Shippy 1984, OpenAlchemist, Mojotron, Seahorse Adventures, Thrust, and Mari0.

[500][501] PlayPower is a non-profit organization founded in 2008 designed to create free educational computer software for low income families in India and other developing countries.