Below is a list of open source games and game-related projects that can be found on GitHub - old school text adventures, educational games, 8-bit platform games, browser-based games, indie games, GameJam projects, add-ons/maps/hacks/plugins for commercial games, libraries, frameworks, engines, you name it.

If you'd like to add a repository to the list, please create an Issue, or fork this repository and submit a pull request.

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• Major Companies
• Browser-Based
  • Boardgame
  • Arcade
  • FPS
  • RPG
  • MMORPG
  • Strategy
  • Racing
  • Sandbox
  • Puzzle
  • Others
• Native
  • Boardgame
  • RPG
  • Puzzle
  • Strategy
• Mobile Games
  • Android
  • IOS
• Just The Source
• Frameworks/Engines/Libraries
• Maps/Hacks/Plugins/Utilities/All of the Things™

A selection of major game studios, publishers, etc. using GitHub:

• 3D Hartwing Chess Set - 3D chess game done in HTML/CSS/JS.
• Green Mahjong - solitaire mahjong game done in HTML/CSS/JS.
• Lichess - Free chess game using HTML5 & websockets, built with scala, Play 2.1, mongodb and elasticsearch. Play now!
• Desperate Gods - a free online board game that was designed to be played just like a board game in real-life: no rules are enforced by the computer. Play it now!

• Alien Invasion - space invaders++. Play it now!
• Asteroids - pure JavaScript asteroids. Play it now!
• Digger - HTML5 version of a Boulderdash game. Play it now!
• Coffee Snake - an HTML5 snake game written in coffee script. Play it now!
• Draconas - a classic shoot 'em up game build with the Three.js library. Play it now!
• hurry! - a small but speedy arcade shooter. Play it now!
• Snake - a clone of the snake game. Play it now!
• Survivor - a playable HTML + CSS + JavaScript remake of a space-based "shoot-'em-up" arcade game for Atari / Commodore 64 from 1982, including a level editor and design tool. Play now!
• Duck Hunt JS - DuckHunt ported to JS and HTML5 with a level creator. Play now!
• Mario 5 HTML - infinite Mario in HTML5 JavaScript - using Canvas and Audio elements. Play now!
• Cell Mates - a GGJ 13 game.
• Codename Lumberjack - a simple flash game written using Actionscript 3.0 and Flixel. Play it now!
• Coil - HTML5 canvas game where you defeat enemies by wrapping enemies in your trail. Play now!
• FlxTeroids - a very simple flixel game inspired by the classic arcade shooter. Play now!
• EKG Runner - a GGJ 13 game.
• Emberwind - HTML5 port of the indie platform game Emberwind. Play now!
• Fluid Table Tennis - renders a table tennis game interacting with a full-color real-time fluid simulation at 60 FPS. Play now!
• FlxInvaders - a very simple flixel game inspired by the Taito classic. Play now!
• Grave Robbers - a sort of GIRP-inspired tower defense. Play now!
• HotFix - help Hotfix collect stargazers and avoid enemies. Collect commits to upgrade hotfix and add new features. Play now!
• Marble Soccer - a marble game for learning three.js.
• Mode - a small (but sadly not that simple) demo game built on the flixel framework. Play now!
• Onslaught Arena - fight off hordes of classic medieval monsters in this fast paced arcade shooter! Play now!
• Pappu Pakia - an addictive game where you guide little Pappu around obstacles while collecting coins, stars, and berries and avoiding enemies known as Pakias. Play now!
• PixelPlatformer - simple platformer game that demostrates the power of the Entity game engine.
• Polybranch - a minimalist 3D game. Dodging branches may seem easy at first, but how long can you hold up as you approach terminal velocity? Play now!
• Release Cycles - n abstract racing game where you fight against the clock and the computer to get as far as you can in a product's life-cycle. Play now!
• Ski Free - a JavaScript port of the classic PC Game, Skifree. Play the Demo now!
• SORADES 13K - a scrolling shooter in the vein of "Raptor: Call of the Shadows" and "Warning Forever". Play now!
• zedinvaders -a game is based on our original comic ZED, seen inside "zero-episode" called "Game Over". Play now!
• Crappy Bird - Flappy bird clone in JavaScript and Canvas2D Api Play now!
• Clumsy Bird - Flappy bird clone in JavaScript using MelonJS Play now!

• BananaBread - a port of the Cube 2/Sauerbraten 3D game engine/first person shooter to the web, compiling C++ and OpenGL to JavaScript and WebGL using Emscripten.

• Diablo JS - Isometric minimal-code style game at html5 canvas and javascript.

• BrowserQuest - an HTML5/JavaScript multiplayer game experiment. Play it now!

• Command & Conquer - clone of the popular RTS. Play it now!
• Tower Defence - 3D Tower Defense build with Three.js in HTML5. Play it now!

• Trigger Rally Online Edition - fast arcade rally racing. Play now!

• Blk Game - a multiplayer Javascript/WebGL voxel world game demo.
• Cube Engine - 3D engine completely written in HTML5 without OpenGL.

• Hextris - an addictive puzzle game inspired by Tetris. Play now!
• Orbium - a modern version of the 90's game Log!cal. Play now!
• Pop Pop Win - an implementation of Minesweeper in Dart.

• HeartLine - a GGJ13 game.
• Squirts - A well-known indie game implemented in JavaScript. Play now!
• The Killer - a flash/as3-based "nongame". Play it now!

• Epic Inventor - an indie, side-scrolling, action, RPG.
• OpenLieroX - Liero clone, like realtime Worms, or a 2D Quake.
• Savage Wheels - 2D car crashing game similar to the old classic Destruction Derby.

• LWJake2 - LWJGL port of Quake 2.
• openspades - Compatible client of Ace of Spades 0.75.

• Arx Fatalis - cross-platform port of Arx Fatalis, a first-person role-playing game.
• Open MW - Reimplementation of the game Morrowind.
• Flare RPG - Fantasy action RPG game with its own engine.
• Valyria Tear - open-source single-player medieval-fantasy 2D J-RPG.

• Commander Genius - Commander Keen compatible clone.
• Escape of the cat - Hardcore oldschool platformer on INSTEAD.
• Frogatto - an action-adventure game, starring a certain quixotic frog.
• Gish - open Source version of the award-winning physics platformer.
• Journey to the Center of Hawkthorne - This 2d platformer is based on Community's Digital Estate Planning episodebuilt using the LÖVE game engine.
• Mario-Level-1 - The first level of Super Mario Bros made with Python and Pygame.

• 2048-cli - A cli version of the game 2048 for your Linux terminal.
• Dominion - a C# implementation of Dominion, a board/card game.
• IRMINGARD - patience card game written in Ruby.
• PuzzleDash - A match-3 puzzle game built in the Dash engine.
• Wizznic - most awesome puzzle game.

• Craft - A simple Minecraft clone written in C using modern OpenGL.
• Minetest - An open source infinite-world block sandbox game with survival and crafting.
• Freeminer - An open source sandbox game inspired by Minecraft.

• Caesaria - an open-source remake of the popular citybuilder and economic sim Caesar III.
• CorsixTH - open source clone of Theme Hospital
• Unknown Horizons - 2D isometric RTS economic strategy game written in C++ & Python, built on the Flexible Isometric Free Engine.
• openage - Open source clone of the Age of Empires II engine.
• OpenRA - an open-source implementation of the Red Alert engine using .NET/mono and OpenGL. Runs on Windows, Linux and OSX.
• OpenXcom - Open-source clone of the original X-Com
• PCOTM (Phone Case of the Monster) - A Ruby game, where you play as a phone-collecting monster.
• Pioneer - A game of lonely space adventure.
• Polly-B-Gone - a physics platform game about a plucky wheeled robot named Polly.
• Source of Tales - an entry in the Liberated Pixel Cup 2012.
• Spring RTS - a powerful free cross-platform RTS engine.
• Voxeliq - an open source block-based game engine implementation developed with C#.
• Wizznic - most awesome puzzle game.

• ChaseWhisplyProject - Chase Whisply is a FPS. You have to seek, find and kill the ghosts living around you.
• Green Mahjong - solitaire mahjong game done in HTML/CSS/JS.

• Bridges - a puzzle game with bridges, houses, tolls, and subways for iOS.
• Canabalt - open source release of Canabalt for iOS.
• Doom - Doom Classic for iOS.
• DrugsNRock - a simple multiplayer rhythm game designed during the Global Game Jam'13.
• Frogatto - an action-adventure game, starring a certain quixotic frog.
• Gorillas - an iPhone (or iPod touch) port of the popular old QBasic game.
• Light Jockey - an iOS Auditorium-like game.
• Lumio - a puzzle game for iOS developed using Cocos2D. Available free on the App Store.
• Wolfenstein 3D - Wolfenstein 3D for iOS Source Release.
• Green Mahjong - solitaire mahjong game done in HTML/CSS/JS.

• Aquaria - a breath-taking underwater fantasy game. Winner of the Grand Prize at the 2007 Independent Games Festival.
• Doom 3 - pew pew pew.
• ID Software - includes Doom, Quake, Wolfenstein and more!
• MaNGOS - a full featured World of Warcraft server!
• Miner Wars 2081 - for modders of Miner Wars 2081, a 6DOF action-survival space-shooter simulation-game set in the year 2081.
• Prince of Persia - Prince of Persia!

• Akihabara - a set of libraries, tools and presets to create pixelated indie-style 8/16-bit era games in Javascript.
• ammo.js - direct port of the Bullet physics engine to JavaScript using Emscripten.
• Babylon.js - a complete JavaScript framework for building 3D games with HTML 5 and WebGL.
• Chipmunk Physics - a simple, lightweight, fast and portable 2D rigid body physics library written in C.
• cocos2d for iphone - a framework for building 2D games, demos, and other graphical/interactive applications for iPod Touch, iPhone, iPad and Mac. It is based on the cocos2d design but instead of using python it, uses objective-c.
• cocos2d-x - a multi-platform framework for building 2d games, interactive books, demos and other graphical applications. It is based on cocos2d-iphone, but instead of using Objective-C, it uses C++. It works on iOS, Android, Windows Phone, OS X, Windows and Linux.
• Dash - A free and open 3D game engine written in D.
• Duality - a 2D Game Development Framework.
• EaselJS - a library to make working with the Canvas element easier.
• EntityJS - an HTML5 javascript game engine utlizing the entity-component design.
• Flashpunk - a free ActionScript 3 library designed for developing 2D Flash games.
• Flixel - an open source game-making library written entirely in ActionScript 3.
• GenesisEngine - GenesisEngine allows you to create and explore procedurally-generated planetary systems, from ground level all the way out into space. Experiments with procedurally-generated worlds, XNA, and design patterns.
• Gladiator 3D - Canvas based JavaScript ray casting engine for pseudo 3D games.
• MonoGame - XNA Implementation for Mono based platforms (supports iOS, Android, Linux, and started work on PS Suite and NaCli ).
• pixi.js - Super fast HTML 5 2D rendering engine that uses webGL with canvas fallback.
• Plasma - Cyan Worlds's Plasma game engine.
• Quasi-Engine - a QtQuick framework that intends to be a complete toolset to ease 2d game development
• Spring - an Open Source Real Time Strategy game engine.
• Tesseract - make mapping more fun by using modern dynamic rendering techniques, sothat you can get instant feedback on lighting changes, not just geometry.
• Torque 3D - MIT Licensed Open Source version of Torque 3D from GarageGames.
• Turbulenz Engine - an HTML5 game engine and server-side APIs available in JavaScript and TypeScript for building and distributing 2D and 3D games.
• melonJS - An open-source HTML5 game framework for 2D games.

• Bfxr - Flash + AIR sound effects generator. Based on Sfxr.
• FlxCollisions - a simple set of 2d physics + collision demos for flixel v2.0. Play now!
• Gamertag - a gem for retrieving Xbox Live Gamertag information from various sources.
• Halo::Reach::API - Ruby gem for interacting with the Halo:Reach API.
• Leaderboard (Java) - Leaderboards backed by Redis (in Java).
• Leaderboard (PHP) - Leaderboards backed by Redis (in PHP).
• Leaderboard (Python) - Leaderboards backed by Redis (in Python).
• Leaderboard (Ruby) - Leaderboards backed by Redis (in Ruby).
• Leaderboard (Scala) - Leaderboards backed by Redis (in Scala).
• libfreenect - drivers and libraries for the Xbox Kinect device on WIndows, Linux, and OS X.
• OpenEmu - an open source project to bring game emulation to OS X as a first class citizen.
• stats.js - JavaScript performance monitor.
• Tassadar - A Starcraft 2 replay parser written in pure Ruby.
• World of Warcraft Addons - too many to list!
• World of Warcraft API Docs - the public documentation for the RESTful web service provided as part of the World of Warcraft community site.