Online

• Netrek (⭐20) - Netrek is a multiplayer battle simulation game with a Star Trek theme. Up to 16 players are divided into two teams that fight each other for dominion over the galaxy.

Strategy

• Tribal Trouble (⭐41) - Tribal Trouble is a realtime strategy game released by Oddlabs in 2004. In 2014 the source was released under GPL2 license.

• Wages of War (⭐0) - A clean-room, open-source Rust reverse enginering of the Wages of War: The Business of Battle (1996) engine.

FPS

• 4TAK (⭐2) - client and server based on q2pro-rerelease and q2pro

• ericw-tools (⭐481) - Quake/Hexen 2 Map compiling tools.

• ew-progs - Eternal War: Shadows of Light's progs source code.

• ew-engine - Eternal War: Shadows of Light's engine source code.

• heavymetal (⭐4) - A static recompilation of Heavy Metal: FAKK2 (2000) targeting modern Windows 11 x86-64.

• lilium-arena (⭐8) - Lilium Arena - Compatible with Quake 3 Arena 1.32.

• lilium-salvation (⭐4) - An engine replacement for Dark Salvation

• lilium-voyager (⭐54) - An engine replacement for Star Trek Voyager: Elite Force Holomatch (multiplayer).

• mint-arena (⭐41) - Spearmint Quake 3 and Team Arena game code.

• mint-metal (⭐18) - Incomplete (unusable for practical purposes) Heavy Metal F.A.K.K.² / American McGee's Alice game code for Spearmint.

• Oblivion-Reconstructed (⭐2) - Reverse-engineered Oblivion Extension Pack source code for original Quake II.

• OmegA-engine (⭐31) - Modern OpenArena engine based on Quake3e

• OmegA-mod (⭐27) - OmegA mod for OpenArena

• openQ4 (⭐56) - The modern binary replacement for QUAKE 4.

• openQ4-game (⭐3) - openQ4 game libraries

• qk1 - Modernized Quake for Unix-like operating systems and 9front.

• qk1 (⭐7) - quake 1 and quakeworld port for plan9.

• q2tools-220 (⭐73) - Quake 2 map compiler tools with v220 map support, automatic phong, enhancements, and fixes.

• qfusion (⭐78) - This is Warsow's fork of qfusion, the id Tech 2 derived game engine.

• quake3-rust-edition (⭐5) - id Tech 3 reimagined in Rust — multiplayer FPS with lag compensation, TDM, demos, and ultra-wide support.

• QL-SRP - Source Reconstruction Project for QUAKE LIVE [WIP]

• realice (⭐9) - Heavy Metal F.A.K.K. 2 / American McGee's Alice reverse engineered.

• REBLIVION (⭐3) - Unofficial ported and enhanced Oblivion Extension Pack for Quake II: Rerelease.

• spearmint (⭐272) - Spearmint — an updated id Tech 3 engine for continuing the classics and creating new games.

• Tremulous110e (⭐0) - Improved Tremulous 1.1.0 engine based on ioquake3

• tremulous (⭐2) - Latest Tremulous based on GrangerHub/tremulous

• MadnessPatch (⭐362) - A patch that fixes various issues in the PC port of Alice: Madness Returns.

• VorpalFix (⭐292) - A patch that addresses various technical issues and adds quality-of-life improvements to the 2011 remaster of American McGee's Alice.

• xash3d-fwgs (⭐2.6k) - Xash3D FWGS engine

RPG

• Amber (⭐10) - Engine for the Amber trilogy

• Ambermoon.net (⭐529) - Ambermoon rewrite in C#

• Arianne RPG - Arianne is an engine to develop multiplayer online games like Stendhal

• castarook (⭐0) - Experience 3D chess with RPG combat, dynamic terrain, and dice-driven battles blending strategy and role-playing elements in a living game world.

• ChaosEsqueAnthology - A free 3d game for PC that does not limit the player. Fight,Build,Gain

• Thirdeye (⭐19) - Reimplementation of AESOP that runs Eye of the Beholder 3 and Dungeon Hack.

Simulator

• dxx-redux (⭐71) - Descent 1&2 source port based on DXX-Retro.

• FLUF - Freelancer Universal Framework

• freelancer-retold - A campaign and gameplay rework for the 2003 game Freelancer.

• forsaken-3ds - Nintendo 3DS port of Forsaken (1998)

• Endless Sky (⭐7.4k) - Space exploration, trading, and combat game.

Strategy

• aeon (⭐2) - Open-source browser god-game & civilization sim where every creature is a real, evolving neural network. Fusion of WorldBox (god sandbox) and Civ (deep progression) - lead a people in Survival or shape the world in Creative. Artificial life, genetic evolution, emergent societies.

• 1oom (⭐100) - 1oom is a Master of Orion Classic (1993) game engine recreation that requires the original files to run.

• Allure (⭐229) - A massive HJSON mod focusing around quick-action, immersive RTS gameplay. Lore package included.

• Beyond-All-Reason (⭐4.1k) - Open source RTS game built on top of the Recoil RTS Engine

• CzechDraughts (⭐0) - Cross-platform Czech Draughts (Česká Dáma) game implemented as a C# console application.

• ChaosGame (⭐0) - chaotic 2D real-time strategy game built from scratch. Command units with random skills, unlock advanced tech trees, and survive the tactical onslaught.

• durer-jatekok (⭐1) - Online version of previous strategy games at Dürer Competition

• Dune-II---The-Maker (⭐359) - A remake of the classic Dune 2 - The Building of a Dynasty (by Westwood Studios) with several enhancements. Like: higher screenresolutions, zooming, multiselect, skirmish play, etc.

• Dune Legacy - Updated clone of Westood Studios' Dune2 which uses data files from the original game.

• Evolution-RTS (⭐150) - Evolution RTS is a free an Open Source RTS game designed using the Spring Engine.

• EmperorReborn (⭐14) - Play Emperor: Battle for Dune on Windows 10 and 11 with real 16:9 widescreen, fullscreen and working multiplayer. Free, open-source launcher and patcher for the Westwood Dune RTS.

• freeserf.net (⭐170) - Settlers 1 clone written in C#

• galaxyofdrones (⭐2) - An open source multiplayer space strategy game.

• GeneralsGameCode (⭐1.2k) - Command and Conquer: Generals - Zero Hour

• grenzmark (⭐2) - Grenzmark is a Godot 4 remake of the Settlers II, Return to the Roots and Widelands

• green-turkiye (⭐0) - Raise awareness of environmental pollution in Turkiye through this engaging strategy game designed to inspire action and promote sustainability.

• grid-wars (⭐2) - AI-generated TRON-themed 3D hex strategy game (three.js): single-player vs the MCP + online multiplayer. Untested — use at your own risk.

• hex-tactics (⭐1) - PIXI.js + React hex-grid tactical battle sandbox — procedural strategic/tactical worlds, a pure-function battle engine, 5 motion modes, and a defendHeight formation system.

• invazion (⭐11) - Azimutant (formerly named "InvaZion") is a collaborative game inspired by Hordes.fr/Die2Nite.

• JS.Hawkoniwa-Island (⭐2) - A homemade island development game inspired by "箱庭諸島". Supports auto-save.

• kiomet (⭐164) - Kiomet.com real-time strategy game (repository commits may lag behind game updates)

• machines (⭐38) - Community fork of Machines: Wired for War

• Mindustry (⭐28k) - The automation tower defense RTS written in Java

• OpenRAG-Skill (⭐1) - Enable evidence-first retrieval augmented generation within Claude Code using prompt-only input and in-chat source material.

• OpenLRR (⭐0) - An open source re-implementation of LEGO Rock Raiders

• OpenFrontIO (⭐2.4k) - Online browser-based RTS game

• Open-Realms-of-Stars (⭐176) - 4X Strategy game.

• opensage-adk (⭐0) - Build AI agents with self-made tools, hierarchical memory, and sandboxed execution for software engineering tasks

• parabellum (⭐24) - An attempt to build a #Travian 3.x clone written in #Rust.

• permafrost-engine (⭐2.8k) - An OpenGL RTS game engine written in C based on Everglory

• Pillage-First-Ask-Questions-Later (⭐162) - An open-source, single-player, Travian alternative browser strategy game, inspired by Travian T4 and Travian Kingdoms

• Rescue Max! - A 2D space real-time, action/strategy game. you are in control of a ship that you fly around space fighting enemies and making friends on your way. The main objective is to rescue people from planets and take them to star bases. its writen in java1.4.

• Rotp-Fusion (⭐63) - Created by Ray Fowler, Remnants of the Precursors is an open-source modernization of the original 1993 Master of Orion.

• rise-of-legions (⭐161) - Rise of Legions is a hybrid of MOBA, tower defense and deckbuilding - with fast-paced, easy-to-pickup tug-of-war strategy. Play solo or bring a friend for co-op or 2v2, collect cards, build your deck and crush your enemies.

• Scorched Earth Online War - Online War system for IL-2 Sturmovik and Iron Front in ArmA 2

• Seven Kingdoms: Ambition - An enhanced version of 7K:AA (Seven Kingdoms: Ancient Adversaries).

• singularity (⭐0) - A simulation of a true AI. Survive, grow, and learn.

• terra-concordia-public (⭐0) - Press kit, release notes & community resources for Terra Concordia — a digital eurogame by NCB Company.

• TheOldWorld (⭐0) - 2D Isometric RTS Game

• thinker (⭐145) - Improved game engine features for SMACX.

• Transarctica-2 (⭐3) - Remake of the classic game Transarctica (In development)

• triplea (⭐1.5k) - TripleA is a turn based strategy game and board game engine, similar to Axis & Allies or Risk.

• ufoai (⭐0) - UFO: Alien Invasion

• Ugh-Guys- (⭐2) - A browser-based, StarCraft-style asymmetric RTS set in a mythic pre-flood world — Three.js + Vite, three factions, fog of war, pathfinding, and an AI opponent. 100% procedural, no external assets.

• Unvanquished (⭐1.1k) - Unvanquished is a free and open source FPS/RTS hybrid game powered by the Daemon game engine. Historically based on Tremulous as a continuation with decades of work over it.

• vaultfront (⭐0) - VaultFront is a browser RTS and a derived AGPL fork of OpenFrontIO, itself evolved from WarFront.io. Created with help from ChatGPT 5.4 and Codex.

• vera20k (⭐7) - Red Alert 2: Yuri's Revenge — rebuilt from scratch in Rust for large multiplayer battles.

• war1 (⭐149) - A remake of Warcraft: Orcs & Humans written in C

• War8 (⭐0) - Turn-based abstract board game built with C++ and SFML, based on "Război în 8" from Nicolae Oprișiu’s "Olimpiada Jocurilor Raționale" ("The Olympiad of Rational Games", Chapter 10). Includes PvP, PvC, CvC, turn timer, HUD, leaderboard, themes, and Easy/Hard AI.

• WarKingdoms (⭐240) - Unity RTS Prototype (Warcraft 3 Style)

• WazzaP's Boss Generals Mod (⭐2) - The official repository of WazzaP's Boss Generals mod for C&C Generals Zero Hour

• Zero-K (⭐813) - Open source RTS game running on the Spring/Recoil engine

Action

• heretic2 (⭐31) - Heretic2 playground sandbox.

• Speed-Academy (⭐19) - Source port of the singleplayer of Star Wars Jedi Knight: Jedi Academy.

• Speed-Outcast (⭐14) - Source port of the singleplayer of Star Wars Jedi Knight II: Jedi Outcast.

Adventure

• Dusklight (⭐4.9k) - Dusklight is a reverse-engineered reimplementation of Twilight Princess.

FPS

• DOOM64EXUltra (⭐4) - A fork of DOOM 64 EX+ with new stuff and fixes

• Q2RTXPerimental (⭐17) - My 'Experimental' fork of NVIDIA’s implementation of RTX ray-tracing in Quake II

Arcade

• Battle City (⭐3) - Browser reimplementation of Namco's 1985 Battle City (Famicom version), built from a full annotated 6502 disassembly. Playable at https://battle-city.berrry.app. 🎴

Action

• Heretic2R (⭐231) - Heretic II (1998, Raven Software) reverse-engineered source port.

Platformer

• Jak Project (⭐3.5k) - The project's goal is to port the original trilogy (Jak 1 -> Jak 3) to PC.

Racing

• Open76 (⭐2) - Interstate '76 engine reimplementation

• SpagettiKart (⭐2.2k) - Reimplementation of Mario Kart 64 for PC.

Simulator

• Descent3 (⭐3) - Descent 3 by Outrage Entertainment

• dxx-vr (⭐4) - Descent 1&2 VR source port based on DXX-Retro

• ForsakenX (⭐178) - Forsaken game engine.

• ForsakenW (⭐10) - The Forsaken source code.

Adventure

• DetectiveDS (⭐5) - A remake of the original C64 classic The Detective Game for Nintendo DS.

• lba1-classic (⭐1) - Little Big Adventure: Twinsen's Adventure Definitive Edition

• lba2-classic-community (⭐100) - Little Big Adventure 2 engine source code.

• lba2remake (⭐282) - A Little Big Adventure 2 / Twinsen's Odyssey reimplementation in JavaScript / Three.js / React.

• twin-e (⭐89) - TwinEngine: a Little Big Adventure engine.

• timeco (⭐7) - Time Commando Reimplementation

Arcade

• AcidDrop (⭐1) - Remake of classic Atari 2600 game "Acid Drop".

• openomf (⭐467) - One Must Fall 2097 Remake.

• Retro-Arcade-Remakes (⭐2) - C++ retro arcade remakes showcasing clean OOP design, game loops, collision systems, and state management.

• SpaceRox.MX2 (⭐1) - 2D Asteroids Style Game using MX2.

• WarhawkDS (⭐2) - Warhawk DS remake of the C64 game Warhawk to the Nintendo DS in native assembler.

FPS

• Barrett (⭐31) - Advanced and featureful Rise of the Triad source port for modern systems.

• Chasm-Reverse (⭐176) - "PanzerChasm" is a free recreation of the game "Chash: - The Rift" by "ActionForms" using the original game data (CSM.BIN file).

• DOOM64-EX-Plus-Enhanced (⭐37) - fork of the Doom 64 EX+ engine, Its main goal is to show what the Doom 64 engine would have looked like if it hadn't been limited by the N64 console.

• EDGE-classic (⭐98) - Cross-Platform OpenGL Doom Source Port with powerful modding features.

• idTech4A++ (Harmattan Edition) (⭐574) - DOOM III/Quake 4/Prey(2006) GLES on Android/Windows/Linux, DOOM 3 BFG/The Dark Mod/RTCW/Quake 1 2 3/GZDOOM/ETW/RealRTCW/OpenJK/SeriousSam/Skin Deep on Android.

• jfsw (⭐96) - Port of the 3D Realms game "Shadow Warrior".

• jftekwar (⭐27) - No-promises port of the Capstone Software game "TekWar".

• jfwhaven (⭐27) - No-promises port of the Capstone Software game "Witchaven".

• OpenChasm (⭐20) - Free software reconstruction of Chasm: The Rift game.

• quakeforge (⭐63) - QuakeForge is descended from the original Quake engine as released by Id Software in December 1999, and can be used to play original Quake and QuakeWorld games and mods (including many modern mods).

• Raze (⭐864) - Build engine port backed by GZDoom tech. Currently supports Duke Nukem 3D, Blood, Shadow Warrior, Redneck Rampage and Powerslave/Exhumed.

• SeriousSamAlphaRemake (⭐31) - Serious Sam Alpha Remake open source project based.

Platformer

• ManicMinerLL (⭐3) - A re-working of Manic Miner onto the DS using levels created for other official computer released versions.

Racing

• dRally (⭐71) - Open Source Engine / Death Rally [1996]

• dethrace (⭐1.2k) - Reverse engineering the 1997 game "Carmageddon"

• hi-octane202x (⭐13) - Hi-Octane with level editor using Irrlicht engine.

• HiOctaneTools (⭐32) - Tools to inspect and modify levels of the game Hi-Octane by Bullfrog (1995).

• tube64 (⭐23) - 64-bit vesion of DOS game Tube (Bullfrog, 1994)

• retruxx (⭐6) - Reverse engineered Hard Truck Apocalypse.

Strategy

• Unciv (⭐11k) - Open-source Android/Desktop remake of Civ V.

• OpenCiv3 (⭐623) - OpenCiv3 is an open-source, cross-platform, mod-oriented, modernized remake of Civilization III by the fan community built with the Godot Engine and C#.

• freeciv (⭐1.6k) - Freeciv is a Free and Open Source empire-building strategy game inspired by the history of human civilization.

• freecivworld - Freecivworld.net is the 3D version of Freeciv.

• Flame (⭐112) - Dungeon Keeper II partial recompilation with bug fixes.

• maxr (⭐44) - A turn based strategy game.

• mc2 (⭐147) - Mech Commander 2 open source engine + OpenGL Linux port.

• MegaGlest (⭐408) - MegaGlest real-time strategy game engine (cross-platform, 3-d).

• OpenDungeonsPlus (⭐25) - Open source game inspired by Dungeon Keeper - Dark, damp and dangerous...

• OPHD (⭐138) - OutpostHD - Open source remake of Sierra On-Line's Outpost.

• OpenCrystalCaves (⭐87) - OCC is an unofficial open source engine reimplementation of the game trilogy Crystal Caves.

• OpenTPW (⭐154) - An open-source re-implementation of Bullfrog's Sim Theme Park / Theme Park World (1999).

• simutrans (⭐85) - Simutrans is a freeware and open-source transportation simulator. 🎴

• Syndicate Wars (⭐229) - Syndicate Wars Fan Expansion, Open Source remake of the classic Bullfrog game.

Arcade

• Crimsonland (⭐163) - Faithful from-scratch rewrite of the twin-stick shooter Crimsonland.

Platformer

• BanjoRecomp (⭐1.9k) - PC Port of Banjo-Kazooie made using N64: Recompiled.

• Ghostship (⭐610) - Super Mario 64 reimplementation for PC.

FPS

• Aleph One (⭐802) - The open source continuation of Bungie’s Marathon 2 game engine.

• Chocolate Quake (⭐206) - A purist Quake source port that restores the original look and feel of v1.09 and earlier.

• Crispy Doom (⭐932) - A limit-removing enhanced-resolution Doom source port based on Chocolate Doom.

• dhewm3 (⭐2.1k) - A source port of Doom 3.

• DSDA-Doom (⭐489) - A successor of prboom+ with extra tooling for demo recording and playback, with a focus on speedrunning and quality of life.

• Eduke32 - Source port of Duke Nukem 3D and the BUILD Engine.

• iortcw (⭐736) - Source port of Return to Castle Wolfenstein.

• ironwail (⭐987) - High-performance QuakeSpasm fork.

• Quake3e (⭐1.5k) - Improved Quake III Arena engine.

• SeriousSamClassic-VK (⭐152) - Open source game engine for Serious Sam Classic with Vulkan support.

• Taradino (⭐56) - SDL2 port of Rise of the Triad.

• UZDoom (⭐2k) - Modder-friendly OpenGL and Vulkan source port based on the DOOM engine. 🎴

• vkQuake (⭐2.2k) - Vulkan Quake port based on QuakeSpasm.

Online

• VoxeLibre - Stable, moddable & free/libre clone of Minecraft based on the Luanti engine. 🎴

FPS

• NearChuckle (⭐47) - A Linux port of Far Cry 1.

• OpenMoHAA (⭐780) - Open re-implementation of Medal of Honor: Allied Assault including Spearhead and Breakthrough expansions.

RPG

• UnderworldGodot (⭐311) - An engine recreation of Ultima Underworld and Ultima Underworld 2 in the Godot Engine.

Platformer

• UnleashedRecomp (⭐4.9k) - An unofficial PC port of the Xbox 360 version of Sonic Unleashed created through the process of static recompilation.

Strategy

• OpenE2140 (⭐68) - Remake of Earth 2140 based on the OpenRA engine (⭐17k)

• OpenKrush (⭐122) - Remake of KKnD (Krush, Kill 'n' Destroy) and KKnD2 based on the OpenRA engine (⭐17k)

• OpenSA (⭐122) - Remake of Swarm Assault based on the OpenRA engine (⭐17k)

• Shattered Paradise (⭐81) - Remake of C&C Tiberian Sun based on the OpenRA engine (⭐17k)

• Romanov's Vengeance (⭐333) - Remake of C&C Red Alert 2 based on the OpenRA engine (⭐17k)

Platformer

• sm64js (⭐10) - Super Mario 64 reimplementation in JavaScript.

Online

• ACEmulator - A custom, completely from-scratch open source server emulator for Asheron’s Call built on C#. 🎴

FPS

• ClassiCube (⭐2k) - Minecraft Classic compatible client written in C from scratch. 🎴

• Doomsday Engine (⭐298) - Source port of id Software's DOOM I/II and Raven Software's Heretic and Hexen. 🎴

Online

• 2004scape - A free & open-source remake of 2004 era RuneScape 2. 🎴

• OpenRSC - Open source accurate RuneScape Classic (2001-2003) game server in Java, based on recorded data and videos. 🎴

• RSC-C (⭐122) - Rewrite of the RuneScape Classic (2001-2003) game client in portable C. 🎴

Strategy

• Ancient Beast (⭐1.9k) - Spiritual successor to Heroes of Might and Magic III focusing on combat; matched based eSport.

Racing

• Reburn 3 (⭐167) - A work-in-progress open source reimplementation of Burnout 3: Takedown.

FPS

• SurrealEngine (⭐1.1k) - The goal of this project is to reimplement enough of the original Unreal Engine to make the Unreal Tournament (UT99) maps playable.

Simulator

• Free Stars: The Ur-Quan Masters - Open source version of the classic Star Control 2.

Action

• OpenRW - A cross-platform, open source re-implementation of Rockstar Games' Grand Theft Auto III.

RPG

• Abyss Engine (⭐267) - Abyss Engine is a game engine designed to run games similar to 2000's style ARPGs such as Diablo II.

Action

• TR1X (⭐946) - Open source implementation of the classic Tomb Raider I game.

Strategy

• GLSMAC (⭐588) - Unofficial open-source OpenGL/SDL2 reimplementation of Sid Meier's Alpha Centauri ( + Alien Crossfire ).

Racing

• wipEout Rewrite (⭐2.9k) - This is a re-implementation of the 1995 PSX game wipEout. 🎴

Strategy

• KeeperFX (⭐975) - Open source remake and Fan Expansion of Dungeon Keeper.

• Ozymandias (⭐2) - An open source re-implementation of Pharaoh in the Julius/Augustus engine.

RPG

• Zelda3 (⭐4.7k) - This is a reverse engineered clone of Zelda 3 - A Link to the Past.

RPG

• OpenEnroth (⭐839) - Might and Magic VI-VIII engine remake using original data & code.

Racing

• Vange-rs (⭐482) - The idea of this project is to replicate the old look and behavior of Vangers, but with native hardware acceleration for the graphics.

Strategy

• VanillaConquer (⭐452) - Command and Conquer and Red Alert original release source port based on the remaster source code drop.

Online

• 2009scape - A free & open-source remake of 2009 era RuneScape 2. 🎴

RPG

• OpenNox (⭐23) - Collaboration project extending the Nox engine.

Strategy

• Stone Kingdoms - A real-time strategy game made with LÖVE based on the original Stronghold by Firefly studios.

Arcade

• OpenJazz (⭐400) - Free, open-source version of the classic Jazz Jackrabbit™ games.

Action

• Rigel Engine (⭐993) - Modern reimplementation of the classic DOS game Duke Nukem II in C++.

FPS

• BetterSpades (⭐278) - Ace Of Spades open source implementation that runs on older machines.

• FreeCS - Free-software re-implementation of Counter-Strike 1.5 running on the FTEQW engine. 🎴

• FTEQW - FPS Engine for Quake 1, QuakeWorld, Quake 2, Hexen II & Quake III Arena.

• Zandronum - Multiplayer oriented port, based off Skulltag, for Doom and Doom II. Also runs Heretic, Hexen and Strife. 🎴

Online

• Space Station 14 (⭐3.7k) - Space Station 14 is a revived attempt at a Space Station 13 remake.

Strategy

• fheroes2 (⭐3.4k) - Free implementation of Heroes of Might and Magic II game engine.

Strategy

• OpenHV (⭐1k) - Open-source implementation of Hard Vacuum. 🎴

Arcade

• OpenTyrian (⭐551) - An open-source port of Tyrian from Turbo Pascal to C. 🎴

Online

• Ryzom Core (⭐445) - Ryzom Core contains the whole code (client, server, tools) used to make the commercial MMORPG Ryzom. 🎴

FPS

• The Force Engine (⭐1.1k) - Jedi Engine for modern systems and the games that used that engine - Dark Forces and Outlaws.

Platformer

• Omnispeak (⭐313) - Reimplementation of Commander Keen in Goodbye Galaxy.

FPS

• BStone (⭐359) - A source port of Blake Stone: Aliens Of Gold and Blake Stone: Planet Strike.

Action

• Carnage3D (⭐552) - Reimplementation of Grand Theft Auto.

• donut (⭐477) - Reimplementation of The Simpsons: Hit & Run in modern C++ and modern OpenGL.

• OpenJK (⭐2.3k) - Community effort to maintain and improve Jedi Academy and Jedi Outcast by Raven Software.

• OpenLara (⭐5k) - Classic Tomb Raider open-source engine.

• OpenMB (⭐140) - Role-playing game engine for Taleworlds' Mount&Blade Series.

• remc2 (⭐142) - Reverse engineering of Magic Carpet 2 from Assembler.

• San Andreas Unity (⭐2.6k) - Reimplementation of GTA: San Andreas game engine in Unity.

• TOMB5 (⭐513) - Tomb Raider: Chronicles disassembly translated to C source code.

Adventure

• ScummVM (⭐2.7k) - Allows you to run certain classic graphical point-and-click adventure games such Maniac Mansion and Monkey Island.

Arcade

• Barbarian - Open-source clone of Barbarian: The Ultimate Warrior.

• C-Dogs SDL (⭐1.1k) - Classic overhead run-and-gun game. 🎴

• Mr.Boom (⭐222) - 8-player Bomberman clone for RetroArch/Libretro.

• OpenClonk (⭐396) - Multiplayer action game where you control small and nimble humanoids.

• Open Kick-Off (⭐57) - Rewriting attempt of the cult football game Kick Off 2. 🎴

• Taisei (⭐1.6k) - Fan-made, open-source clone of the Touhou series. 🎴

• The Great Escape in C (⭐128) - Classic ZX Spectrum game The Great Escape in portable C. 🎴

• Zelda Classic (⭐38) - A game and editing tool that lets you create custom Legend of Zelda quests.

FPS

• Allegiance (⭐101) - Allegiance is RTS and FPS Space Combat game.

• CatacombGL (⭐186) - Windows source port of Catacomb 3D and the Catacomb Adventure series.

• Chocolate Doom (⭐2.4k) - Source port that is minimalist, historically accurate and includes ports of Heretic and Hexen, and Strife. 🎴

• Doom Legacy - One of the most popular DOOM source ports, which enhances it with things like TCP/IP networking, OpenGL renderer etc. 🎴

• DoomRetro (⭐760) - Classic, refined DOOM source port for Windows PC. 🎴

• DukeGDX - Duke Nukem 3D port.

• ECWolf - Port of Wolfenstein 3D based on Wolf4SDL.

• ezQuake (⭐405) - Combining the features of all modern QuakeWorld clients, ezQuake makes QuakeWorld easier to start and play.

• Freedoom (⭐1.3k) - Free software FPS based on the classic DOOM engine. 🎴

• Hexen II: Hammer of Thyrion - Cross-platform port of the Hexen II game.

• ioquake3 (⭐2.8k) - The free software FPS engine that can be used to play Quake 3, or make your own game.

• NBlood (⭐781) - Port of the classic FPS Blood.

• Odamex (⭐277) - Online multiplayer DOOM port with a strong focus on the original gameplay while providing a breadth of enhancements. 🎴

• OpenSpades (⭐1.2k) - Compatible client of Ace of Spades, a voxel FPS.

• QuakeSpasm - A modern, cross-platform Quake game engine.

• RBDOOM-3-BFG (⭐1.8k) - Doom 3 BFG Edition with soft shadows, cleaned up source, Linux and 64 bit Support.

• RedneckGDX - Port of Redneck Rampage.

• The Eternity Engine (⭐264) - Advanced DOOM source port. 🎴

• Tyrquake (⭐47) - Libretro port of Tyrquake.

• Yamagi Quake II (⭐985) - Enhanced client for id Software's Quake II with focus on offline and coop gameplay.

Online

• 2006rebotted (⭐36) - A 2006 RuneScape 2 Emulation Server. 🎴

• FreeSO (⭐954) - Reimplementation of The Sims Online, targetted mainly at mobile devices. 🎴

• Meridian 59 (⭐501) - The first 3D MMORPG, released in 1996 and open sourced in 2012. The original codebase for Meridian 59.

• Opengate - Remake of Jumpgate.

• RuneLite (⭐5.4k) - Open source Old School RuneScape (OSRS) client. 🎴

RPG

• Arx Libertatis (⭐1.1k) - Cross-platform port of Arx Fatalis, a first-person role-playing game.

• Barony (⭐688) - Open source release of Barony.

• BtBuilder (⭐48) - An open source implementation of the Bard's Tale Construction Set.

• Daggerfall Unity (⭐3.4k) - Recreation of Daggerfall in the Unity engine.

• Devilution (⭐9k) - Reconstructed form of Diablo's original source code.

• DevilutionX (⭐9.6k) - Diablo build for modern operating systems.

• DGEngine (⭐271) - Implementation of the Diablo game engine.

• Exult (⭐666) - Project to recreate Ultima 7 for modern operating systems.

• Falltergeist (⭐887) - Crossplatform Fallout 2 game engine writen in C++ and SDL.

• Freeablo (⭐2.2k) - Open-source implementation of the Diablo engine.

• FreeFT (⭐189) - Real-time, isometric action game engine inspired by Fallout Tactics.

• GemRB (⭐1.2k) - Portable open-source reimplementation of the Infinity Engine (used by Baldur's Gate, Icewind Dale and more).

• OpenGothic (⭐1.6k) - Reimplementation of Gothic 2: Night of the Raven.

• OpenMW (⭐6.4k) - Reimplementation of the Morrowind game engine.

• OpenTESArena (⭐1.3k) - Modern engine reimplementation of The Elder Scrolls: Arena by Bethesda Softworks.

• OpenVIII (⭐677) - Final Fantasy VIII engine implementation in C#.

• REGoth (⭐500) - An open source reimplementation of zEngine the engine behind Gothic and Gothic II.

• Riiablo (⭐1.1k) - Diablo II remade using Java and LibGDX.

• sfall (⭐428) - A set of engine modifications for the classic game Fallout 2.

• Shockolate (⭐895) - Same great System Shock, new great taste.

• UAlbion (⭐164) - Remake of 1995 Albion.

• WitchavenGDX - Witchaven Java port.

• xoreos (⭐1.2k) - Implementation of BioWare's Aurora engine and its derivatives (used by Neverwinter Nights, The Witcher and more).

• zorkClone (⭐19) - Reimplementation of the original Zork game developed by Infocom.

Platformer

• Alive Reversing (⭐429) - Reimplementation of Oddworld: Abe's Exoddus.

• Commander Genius - Modern Interpreter for the Commander Keen Games. 🎴

• Jazz² Resurrection (⭐556) - Reimplementation of Jazz Jackrabbit 2.

• Lionheart Remake (⭐87) - Java remake of Lionheart Amiga game.

• NXEngine-evo (⭐543) - Rewrite of the masterpiece jump-and-run platformer Doukutsu Monogatari (also known as Cave Story).

• Prince-Monogame (⭐53) - Monogame implementation of Prince of Persia 2.

• SDLPoP (⭐1.3k) - Port of Prince of Persia, based on the disassembly of the DOS version.

• The Secret Chronicles of Dr. M (⭐223) - Adaptation of Secret Mario Chronicles. 🎴

• VVVVV (⭐8k) - The source code to VVVVVV.

Racing

• DreeRally (⭐100) - Death Rally engine reimplementation.

• OpenNFS (⭐806) - Attempt to recreate the classic Need for Speed Games (1-6).

• Vangers (⭐726) - Racing/RPG hybrid made open-source by its creators, written in C++.

Simulator

• DXX-Rebirth (⭐623) - Source port of the Descent and Descent 2 Engines for Windows, macOS, Linux.

• FS2Open (⭐477) - FreeSpace2 Source Code Project.

• Librelancer (⭐592) - Reimplementation of the 2003 space game Freelancer.

Strategy

• Antares (⭐110) - Remake of Ares, a tactical space combat game.

• CivOne (⭐261) - Implementation of Sid Meier's Civilization.

• CorsixTH (⭐4.5k) - Clone of Theme Hospital with support for modern operating systems, high resolutions and much more.

• Cortex Command Community Project Source (⭐203) - Community-driven effort to continue the development of Cortex Command.

• FreeCol - Turn-based strategy game based on the old game Colonization.

• Jagged Alliance Stracciatella (⭐522) - Makes Jagged Alliance 2 available on a wide range of platforms.

• Julius (⭐3.3k) - Reimplementation of Caesar III.

• KaM Remake (⭐376) - RTS game remake of Knights and Merchants written in Delphi from scratch.

• KeeperRL (⭐986) - Roguelike dungeon builder inspired by Dwarf Fortress.

• openage (⭐14k) - Clone of the Age of Empires II engine.

• OpenApocalypse (⭐580) - Rebuild of the X-COM: Apocalypse engine.

• openblack (⭐1.5k) - Reimplementation of Black & White.

• OpenDUNE (⭐1.7k) - Recreation of the popular game Dune II.

• Open Fodder (⭐595) - Open-source implementation of Cannon Fodder.

• OpenLoco (⭐1.7k) - Reimplementation of Chris Sawyer's Locomotion.

• Open Panzer (⭐183) - HTML5 Panzer General 2. 🎴

• OpenRA (⭐17k) - Implementation of the Red Alert engine using .NET/mono and OpenGL. Runs on Windows, Linux and macOS.

• OpenRCT2 (⭐16k) - Recreation of RollerCoaster Tycoon 2.

• OpenSAGE (⭐1.6k) - C# reimplementation of SAGE, the game engine used by a bunch of EA Pacific games, including Command & Conquer: Generals and Battle for Middle Earth.

• OpenSC2K (⭐5.1k) - Remake of SimCity 2000 by Maxis.

• OpenTTD (⭐8k) - OpenTTD is a transport simulation game based upon the popular game Transport Tycoon Deluxe, written by Chris Sawyer. 🎴

• OpenXcom (⭐2.2k) - Clone of UFO: Enemy Unknown and X-COM: Terror From the Deep.

• OutpostHD (⭐138) - Remake of Sierra On-Line's Outpost.

• Race into Space (⭐211) - Version of Interplay's Buzz Aldrin's Race into Space.

• Return To The Roots (⭐579) - Settlers II remake written in C++.

• Sourcehold (⭐278) - Implementation of Stronghold by Firefly Studios.

• VCMI (⭐5.7k) - Engine for Heroes of Might and Magic III.

• Wargus (⭐424) - Warcraft 2 Mod that allows you to play Warcraft 2 with the Stratagus engine.

• Warzone 2100 (⭐3.9k) - Free and open-source real time strategy game. 🎴

• Zed Online - Remake of the 1996 classic game Z.