See also Emulation
- https://github.com/AdelKS/LinuxGamingGuide - An incomplete compilation of things that may improve the gaming experience on Linux
- Linux game database - primarily for Linux games that are beyond the planing stage and have released more than tech demos, ether as source code or binary files. The information about a game is usually taken from the game site. The games are carefully categorized and presented with screenshots and videos. The submission guidelines explain what kind of Linux games are in the database. You can browse the database whilst applying a lot of filters to tweak the output. This site uses two methods to rank games: user votes and popularity. Popularity is the sum of visits for the past three days.
- Free Gamer - Open Source Games blog
- Open Source Game Clones - This site tries to gather open-source remakes of great old games in one place. If you think that something is missing from the list - please go to our GitHub repository and create an issue or even a pull request! Since all these projects are open-source you can help them and make this world a better place. Or at least you can play something to appreciate the effort people put in them.
- Mari0 - Two genre defining games from completely different eras: Nintendo's Super Mario Bros. and Valve's Portal. These two games managed to give Platformers and First-Person Puzzle Games a solid place in the video game world. But what if Nintendo teamed up with Valve and recreated the famous Mario game with Portal gun mechanics?
The times have found us
- PCGamingWiki - an encyclopedia of PC game fixes
- https://github.com/Davidslv/rogue - Original Rogue Game (5.4.4)
- https://github.com/angband/angband - A free, single-player roguelike dungeon exploration game
- Arduboy - a miniature game system the size of a credit card. It comes installed with a classic 8-bit game and can be reprogrammed from a library of open source games available online. Arduboy is open source so you can learn to code and create your own games.
- Godot Engine - provides a huge set of common tools, so you can just focus on making your game without reinventing the wheel. Godot is completely free and open source under the very permissive MIT license. No strings attached, no royalties, nothing. Your game is yours, down to the last line of engine code.
- https://github.com/ligurio/awesome-ttygames - Unix ASCII games
- DynaHack - A NetHack variant with randomized equipment, new items, new monsters, new maps, new challenges and an advanced ASCII interface.
- http://www.asciisector.net/ - cliish
- https://en.wikipedia.org/wiki/Maze_War - (also known as The Maze Game, Maze Wars, Mazewar or simply Maze) is a 1973 computer game which originated or disseminated a number of concepts used in thousands of games to follow, and is considered one of the earliest examples of, or progenitor of, a first-person shooter. Uncertainty exists over its exact release date, with some accounts placing it before Spasim, the earliest first-person shooter with a known time of publication. Although the first-person shooter genre did not crystallize for many years, Maze War influenced first-person games in other genres, particularly RPGs. The Maze War style view was first adopted by Moria in 1975, an early RPG on the PLATO network, and further popularized by Ultima and Wizardry, eventually appearing in bitmapped form in games like Dungeon Master, Phantasy Star, Eye of the Beholder and countless others.
- Ars Technica: Want to see gaming’s past and future? Dive into the “educational” world of PLATO - The PLATO system was designed for education. It had a programming language called TUTOR that was simple enough for non-technical people to use for writing software; it also notably offered a social environment. It was an online community as much as it was a computing platform, and in this capacity it envisaged much of the future of communication. PLATO had chat rooms, message boards, touch panels built into the (flat, plasma) screens, emoticons, animations, virtual economies, and more.
For those who wish to try the games described in this article: you can register an account and download a terminal emulator from cyber1.org, which will grant access to notesfiles—which were used as message boards—and thousands of lessons. Some of these are games. If you've never used a PLATO terminal before, you may struggle at first, but there's plenty of help available to support you. I'd recommend you enter the phrase "bigjump" (without quotes) once you get to the Author Mode display, as that gives quick and easy access to everything else and gets you past the initial "huh?" hurdle of using non-GUI computing platforms. But PLATO also had a less heralded but equally influential component. And even if history has glossed over this detail and neglected to celebrate it, PLATO's gaming archives remain unforgettable for anyone who was there to experience the platform. These "lessons" infuriated administrators, delighted students, and, importantly, pushed the system to its limits. 
- cyber1 - the name for our mainframe-based CYBIS system. To those familiar with PLATO, CYBIS, or early NovaNET, cyber1 will feel like coming home again. Cyber1 runs on top of NOS, the CDC mainframe operating system, generously contributed by BT Consulting & Systems Integration Services (formerly Syntegra). NOS in turn runs on top of DtCyber (watch out, this is a link to a .pdf), a software emulation of a CDC Cyber mainframe, created by Tom Hunter.
- http://www.shikadi.net/moddingwiki/Main_Page - Welcome to the DOS Game Modding Wiki! The goal of this wiki is to assist people wishing to modify DOS games (typically those released for the PC in the early 1990s) to create entirely new games. The wiki attempts to document all the file formats used by each game to assist programmers writing editing tools, as well as listing any existing tools that can already be used to modify the game.
- https://github.com/zladovan/gorched - Gorched is terminal based game written in Go inspired by "The Mother of all games" Scorched Earth
- https://github.com/MutantStargoat/88tris - bootable text-mode tetris for the original IBM PC
- YouTube: Making the NES Super Mario Bros with C++ and SFML - SFML Tutorial
- https://github.com/Kofybrek/Super-Mario-Bros - Remake of the original Super Mario Bros game.
- Space Station 14 - tells the story of an ordinary shift on a space station gone wrong. Immerse yourself into your role, tinker with detailed systems, and survive the chaos in this round-based multiplayer role playing game.Your custom character can spawn as one of dozens of crew and enemy jobs, ranging from engineer to captain, or even a traitor, each with its own unique gear. Your duties guide you through rich interactions with complex mechanics, whether you're managing your inventory, setting up the reactor, or flushing yourself down the disposal tubes.As disaster, incompetence, and sabotage strike the station, the tension rises - opening up emergent situations that force you to make hard choices. Will you patch up the medical bay after an asteroid punches a hole in it, or fight for control when the captain gets murdered by revolutionaries? Do you break out an unjustly imprisoned clown, or sit back at the bar and serve drinks without a care in the world?The story of the station's collapse is in the hands of its players, and each round is an intense, immersive experience that will leave you wanting more.SS14 is a remake of the cult classic Space Station 13. The game is under active development and completely open source. Anybody can contribute, even you! 
- https://github.com/openglad/openglad - a port of the open-sourced dos game known as Gladiator(http://fsgames.com/glad/). It is a top-view gauntlet style RPG thatfeatures fast paced multiplayer action, several different classes, anda scenario editor.
- Deliantra MMORPG - a thrilling MMORPG in a retro, pixel art world where magic and monsters abound.
- https://github.com/diasurgical/devilutionX - Diablo build for modern operating systems
- https://github.com/ljbade/wolf4sdl - an open-source port of id Software's classic first-person shooter Wolfenstein 3D to the cross-platform multimedia library SDL. It is meant to keep the original feel while taking advantage of some improvements.
- Eureka DOOM Editor | HomePage - a map editor for the classic DOOM games, and a few related games such as Heretic and Hexen. It supports Linux, Windows and OS X
- Doomsday Engine - a Doom / Heretic / Hexen port with enhanced graphics
- ZDoom - GZDoom is a feature centric port for all Doom engine games, based on ZDoom, adding an OpenGL renderer and powerful scripting capabilities
- https://github.com/viti95/FastDoom - Doom port for DOS, based on PCDoom by @nukeykt. The goal of this port is to make it as fast as posible for 386/486 personal computers.
- https://jmtd.net/wadc - a programming language (formally, a normal-order evaluated functional language1) for the construction of Doom maps. Think of it like Logo on steroids, with demons and shotguns.
- https://github.com/fabiangreffrath/crispy-doom - Limit-raising medium-resolution Doom source port based on Chocolate Doom
- OBLIGE - Random map generator for classic FPS games
- https://github.com/caligari87/ObAddon - A repository of community-built prefabs and other enhancements for Oblige
- https://github.com/Realm667/WolfenDoom - Blade of Agony is much more than just a pastiche of the classic shooters that inspired it; the project will offer a unique experience. It also has many features not often seen in source port projects--Blade of Agony truly pushes GZDoom to its limits.
- https://github.com/maximevince/fbDOOM - Adaptation of the original DOOMto be easily portable to framebuffer devices with minimal depenencies.
- https://github.com/viciious/d32xr - Sega 32X port of Doom
Duke Nukem 3D
- EDuke32 - an awesome, free homebrew game engine and source port of the classic PC first person shooter Duke Nukem 3D— Duke3D for short—to Windows, Linux, Mac OS X, FreeBSD, several handhelds, your family toaster, and to your girlfriend's vibrator. We've added thousands of cool and useful features and upgrades for regular players and additional editing capabilities and scripting extensions for homebrew developers and mod creators. EDuke32 is open source software that is completely free to use for all non-commercial purposes.
- https://github.com/lethal-guitar/RigelEngine - A modern re-implementation of the classic DOS game Duke Nukem II
- https://github.com/nukeykt/NBlood - Reverse-engineered ports of Build games using EDuke32 engine technology and development principles (NBlood/Rednukem/PCExhumed)
Dark Forces / Outlaws
- https://github.com/luciusDXL/TheForceEngine - project to reverse engineer and rebuild the Jedi Engine for modern systems and the games that used that engine - Dark Forces and Outlaws. The project includes modern, built-in tools, such as a level editor and makes it easy to play Dark Forces and Outlaws on modern systems as well as the many community mods designed to work with the original games.
- https://en.wikipedia.org/wiki/QuakeWorld - an update to id Software's seminal multiplayer deathmatch game, Quake, that enhances the game's multiplayer features (namely UDP support) to allow people with dial-up modems to achieve greatly improved responsiveness when playing on Internet game servers.
- https://github.com/Novum/vkQuake - port of id Software's Quake using Vulkan instead of OpenGL for rendering. It is based on the popular QuakeSpasm and QuakeSpasm-Spiked ports and runs all mods compatible with QuakeSpasm like Arcane Dimensions.Compared to QuakeSpasm vkQuake also features a software Quake like underwater effect, has better color precision, generates mipmaps for water surfaces at runtime and has native support for anti-aliasing and AF. Due to the port using Vulkan and other optimizations it can also achieve much better frame rates. Code ported from QuakeSpasm-Spiked makes it possible to run the game at over 72FPS without breaking physics.
News and info
- Qaddicted.com - Quake fan-site offering a complete-as-can-be singleplayer map archive with an accompanying install & launch tool, several rather messy archives (engines, tools, wads, multiplayer maps, websites) and a variety of articles, knowledge and help.
- Quake Owner's Manual - By Johnny Law. All the fundamentals of configuring Quake. Includes specific setups for widescreen support, mouselook, and more.
- How To Play Classic Quake on Linux - July 2014, Carla Schroder
- ezQuake — Modern QuakeWorld Client. Combining the features of all modern QuakeWorld clients, ezQuake makes QuakeWorld easier to start and play. The immortal first person shooter Quake in the brand new skin with superb graphics and extremely fast gameplay.
- nQuake - a complete QuakeWorld package consisting of ezQuake, configs, textures and everything else you need to get started with QuakeWorld in a matter of minutes. It currently supports Windows, Linux and Mac.
- Fodquake - fork of FuhQuake, takes the experience to a new level, gives you a vast number of enhancements and new features. A QuakeWorld client for sensible people who expect (or not) higher level of happiness, so it is easier to frag, die and smile.
- classicQ - a free eSports extension to the original Quake 1. It has been created to commemorate the 20th anniversary of Quake. Join the true gaming underground and play online on the QuakeWorld servers!
- QuakeForge - a 3D first-person shooter game engine based on id Software's legendary Quake and QuakeWorld game engines. Our purpose is to improve the state of the game by improving the engine, making a good base for game and engine modifications, and making it accessible to the largest number of players we can. We like it, and we think you will too.
- Quakespasm - An engine for iD software's Quake. With single player extension mods.
- Tenebrae - a modification of the quake source that adds stencil shadows and per pixel lights to quake. Stencil shadows allow for realistic shadow effects on every object in the game world. Per pixel lighting allows you to have fine surface details correctly lit. These are essentially the same algorithms as used by the new Doom game.
- Darkplaces - a source port for Quake maintained by LordHavoc. It is focused around single-player and is compatible with most of the mods made for Quake. However, it can be played with bots as well.
- TyrQuake - to satisfy my programming itch, fix any bugs I find and keep the codebase working on modern compilers and runtime environments. I like to support features which enable map designers to create larger and/or more detailed maps than the original game allowed for. What I don't intend to do is to changing the look or feel of the original game, with some exceptions for various non-intrusive or optional features such as smoother model animations, coloured lighting, fullbrights in GLQuake, etc.
- https://github.com/SiPlus/WebQuake 
- https://github.com/shaunlebron/blinky - Proof of concept to put peripheral vision into games (without VR goggles). Explore this interesting space by playing the Quake demo with fisheyes, panoramas, and cartographic projections. 
- Announcing Handmade Quake - a series of videos and blogs where I rebuild the original Quake from scratch, line by line, system by system. It is named Handmade Quake thanks to the inspiration of the Handmade Dev community, and following the spirit of their manifesto, we will be starting with a blank Visual Studio project, nothing pre-written at all, and file by file, will turn it into the source code that id Software released to the world in late 1999. 
The game contains a client and server component so anyone can host a game. Headless server option is available.
- https://github.com/RobSis/quake-portal-gun - Quake modification, that adds Portal Gun.
- http://www.gamefront.com/files/9503202 - team fortress
- Quake Injector - a tool to make downloading, installing and playing custom Quake maps (and singleplayer Quake-style mods) easy and convenient. Initially designed by Spirit and written by megaman.
wget -r -np -l 1 -A zip http://bigfoot.morphos-team.net/misc/quakemaps/
- https://github.com/Jason2Brownlee/QuakeBotArchive - Archive of all Quake 1 bots.
Quake 3 Arena
- ioquake3 – Free Software FPS Game Engine Based on Quake 3 for Windows, Linux, and macOS
- https://github.com/ec-/Quake3e - a modern Quake III Arena engine aimed to be fast, secure and compatible with all existing Q3A mods. It is based on last non-SDL source dump of ioquake3 with latest upstream fixes applied.
- Pre configured q3config.cfg - ioquake3 - ioquake community forums -
- YouTube: Strafe-jumping physics explained
- YouTube: Genesis - The Beginning Of (Part 1)
- q3df.org | Wiki > Defrag Documentation > CrosshairStats-CHS1
- Defrag.ru Community :: Рекорды по картам - vq3 demos
- Defrag.ru Community :: Рекорды по картам - cpm demos
- navy seals: covery operations (ns:co)
- https://github.com/rein4ce/hlbsp - Half-Life WebGL level and model viewer
- Aleph One - the open source continuation of Bungie’s Marathon 2 game engine. Available for Mac OS X, Windows, and Linux, Aleph One supports Marathon, Marathon 2 and Marathon Infinity natively. Many third party scenarios and net maps are also available.
The Elder Scrolls
- https://github.com/afritz1/OpenTESArena - Open-source re-implementation of The Elder Scrolls: Arena.
- OpenMW - an open-source open-world RPG game engine that supports playing Morrowind.
- https://github.com/feather-rs/feather - A Minecraft server implementation in Rust
- Minetest - Open source voxel game engine - An open source voxel game engine. Play one of our many games, mod a game to your liking, make your own game, or play on a multiplayer server.Available for Windows, macOS, GNU/Linux, FreeBSD, OpenBSD, DragonFly BSD, and Android.
- Mesecons - Mesecons is a mod for the free, open source game Minetest. Mesecons adds everything digital, from all kinds of sensors, switches, solar panels, detectors, pistons, lamps, sound blocks to advanced digital circuitry like logic gates and programmable blocks.
- https://github.com/9mine/9mine - mod for Minetest with p9
- Marble Marcher by CodeParade - entirely ray-traced in real time and is played on the surface of evolving fractals. The goal is to get your marble to the goal as quickly as possible. There are 15 unique levels to master. 
- Citybound - A city building game that uses microscopic models to vividly simulate the organism of a city arising from the interactions of millions of individuals.
- Arx Libertatis - a cross-platform port of Arx Fatalis - a cross-platform, open source port of Arx Fatalis, a 2002 first-person role-playing game / dungeon crawler developed by Arkane Studios.
- https://gitlab.com/veloren/veloren - multiplayer voxel RPG written in Rust. Veloren takes inspiration from games such as Cube World, Minecraft and Dwarf Fortress. The game is currently under heavy development, but is playable.
- https://github.com/trigger-segfault/OpenLRR - An open source re-implementation of LEGO Rock Raiders rockpick
- https://dhewm3.org/ - a source port of the original Doom3 (not Doom3 BFG, for that you may want to try RBDoom3BFG). It's known to work on Windows, Linux, macOS, FreeBSD, OpenBSD and AROS, but it should work on (or be easily portable to) any system that supports OpenGL 1.4 with ARB shaders, SDL and OpenAL.Compared to the original version of Doom3, dhewm3 has many bugfixes, supports EAX-like sound effects on all operating systems and hardware (via OpenAL Softs EFX support), has much better support for widescreen resolutions and has 64bit support. It only supports old Mods if they either don't require their own game DLL or have been ported to dhewm3 - see the Mods page for more information.Note that while the Doom3 source code has been released under GPL, you still need to legally own the game and provide dhewm3 the game data to play.
- https://github.com/GTAmodding/re3#screenshots - GTA III, Vice City
- Veloren - an open-world, open-source multiplayer voxel RPG. The game is in an early stage of development, but is playable.
Space Nerds In Space
- Clone Hero - a free rhythm game, which can be played with any 5 or 6 button guitar controller, game controllers, or just your standard computer keyboard. Download the game, copy your song charts into the song folder and enjoy hours of fun!
- Torrents - beatmaps
- osu!search - Search osu! beatmaps
- https://github.com/sciboy12/Abs - Use your touchpad to play osu! on Linux
- https://github.com/sciboy12/Abs-C - Abs ported to C
- https://github.com/alex-tee/ion - Circle-clicking rhythm game
- https://github.com/jeremy-collette/midistar - a free game that challenges users to play MIDI songs using their computer keyboard or electronic MIDI instruments such as drums or piano
- https://en.wikipedia.org/wiki/UltraStar - a clone of SingStar, a music video game by Polish developer Patryk "Covus5" Cebula. UltraStar lets one or several players score points by singing along to a song or music video and match the pitch of the original song as well. UltraStar displays lyrics as well as the correct notes similar to a piano roll. On top of the correct notes UltraStar displays the pitch recorded from the players. UltraStar allows several people to play simultaneously by connecting several microphones possibly to several sound cards. To add a song to UltraStar, a file with notes and lyrics is required, together with an audio file. Optionally a cover image, a backdrop image and a video may be added to each song. UltraStar comes preloaded with a short sample from Nine Inch Nails hit "Discipline" from The Slip album.
- UltraStar Deluxe - a free open source karaoke game for your PC. The gameplay experience is similar to that of the commercial product SingStar™ by Sony Computer Entertainment, which is exclusively available for the Playstation®.Unlike SingStar™, however, UltraStar Deluxe allows users to create their own songs and sing them on their PC.
- Vocaluxe - a free and open source singing game, inspired by SingStar™ and the great Ultrastar Deluxe project. It allows up to six players to sing along with music using microphones in order to score points, depending on the pitch of the voice and the rhythm of singing.
- https://github.com/Interrupt/systemshock - a cross platform source port of System Shock, using SDL2. This runs well on OSX, Linux, and Windows right now, with some missing features that need reviving due to not being included in the source code that was released.The end goal for this project is something like what Chocolate Doom is for Doom: an experience that closely mimics the original, but portable and with some quality of life improvements including an OpenGL renderer and mod support!
- https://github.com/cuckydev/SoniCPort - Sonic the Hedgehog (1991, Sega Genesis / MegaDrive) C Port
- Sonic 2 Community's Cut - A combined mod of Sonic 2 and the Genesis Plus GX emulator which adds widescreen, S2 2013 enhancements, and a whole lot more.
- https://github.com/heyjoeway/s2cx - Sonic 2 Community's Cut (meta repository)
- Open Fodder - An open source port of Cannon Fodder
- openage - A free (as in freedom) clone of the Age of Empires II engine
- Memory of a Broken Dimension
- SuperTux - a open-source classic 2D jump'n run sidescroller game in a style similar to the original Super Mario games.
- SuperTuxKart - a 3D open-source arcade racer with a variety characters, tracks, and modes to play. Our aim is to create a game that is more fun than realistic, and provide an enjoyable experience for all ages. In Story mode, you must face the evil Nolok, and defeat him in order to make the Mascot Kingdom safe once again! You can race by yourself against the computer, compete in several Grand Prix cups, or try to beat your fastest time in Time Trial mode. You can also race with up to four friends on one PC, or battle each other in multiplayer arenas. Network multiplayer modes are currently under development.
- Tuxemon - a completely free, open source turn-based monster fighting RPG. Tuxemon has been completely written from scratch and contains all original code. In the spirit of other open source clones like SuperTux and SuperTuxKart, Tuxemon aims to create an open source game with its own unique style that sets it apart from other monster fighting RPGs.
- Tux Racer - lets you take on the role of Tux the Linux Penguin as he races down steep, snow-covered mountains. Enter cups and compete to win the title! Tux Racer includes a variety of options for gameplay, including the ability to race courses in fog, at night, and under high winds.
- Extreme Tux Racer - High speed arctic racing game based on Tux Racer.
- Legacy of Norrath - A pure, nostalgic, Everquest experience, where YOU are in control of your destiny. In-Era pre-nerf items, spells, tradeskills, with quality of life addons to those aspects! Classic graphics, spell effects, spell icons, and spell gems enhanced by the newer client. Increased out-of-combat health and mana regeneration. Classic items such as Guise of the Deceiver, Manastone, Terror Forged Mask are there for your taking! All of this brought to you by experienced, battle-hardened veteran developers who take pride in offering a unique classic experience.
- http://tesseract.gg/ - forked from Cube 2: Sauerbraten
- https://github.com/TheFakeMateo/RedPlusPlus - Pokemon Red rework
- Critical Mass - Your world has been infested by an aggressive army of space critters. Overrun and unprepared, your government was unable to defend its precious resources. As a last effort to recapture some of the "goodies", you have been placed into a tiny spacecraft and sent after them.
- OpenSpades - a clone of Ace of Spades 0.75, which is a free online first-person shooter created by Ben Aksoy, featuring fully destructible terrain and plenty of game modes (including the well-known Capture the Flag) created by the community.
- MAME - a multi-purpose emulation framework. MAME's purpose is to preserve decades of software history. As electronic technology continues to rush forward, MAME prevents this important "vintage" software from being lost and forgotten. This is achieved by documenting the hardware and how it functions. The source code to MAME serves as this documentation. The fact that the software is usable serves primarily to validate the accuracy of the documentation (how else can you prove that you have recreated the hardware faithfully?). Over time, MAME (originally stood for Multiple Arcade Machine Emulator) absorbed the sister-project MESS (Multi Emulator Super System), so MAME now documents a wide variety of (mostly vintage) computers, video game consoles and calculators, in addition to the arcade video games that were its initial focus.
- Apps/GnomeVideoArcade - GNOME Wiki! - a simple Mame frontend for any freedesktop.org compliant desktop environment. GNOME Video Arcade recognizes that the frontend is not the point; the games are. As such, its chief design goal is to help you quickly find a game to play and then get out of the way. Its purpose is not to help you manage your ROM collection, nor to provide a confusing graphical interface for MAME's plethora of configuration options.
- A Slower Speed of Light - a first-person game prototype in which players navigate a 3D space while picking up orbs that reduce the speed of light in increments. Custom-built, open-source relativistic graphics code allows the speed of light in the game to approach the player’s own maximum walking speed. Visual effects of special relativity gradually become apparent to the player, increasing the challenge of gameplay. These effects, rendered in realtime to vertex accuracy, include the Doppler effect (red- and blue-shifting of visible light, and the shifting of infrared and ultraviolet light into the visible spectrum); the searchlight effect (increased brightness in the direction of travel); time dilation (differences in the perceived passage of time from the player and the outside world); Lorentz transformation (warping of space at near-light speeds); and the runtime effect (the ability to see objects as they were in the past, due to the travel time of light). Players can choose to share their mastery and experience of the game through Twitter. A Slower Speed of Light combines accessible gameplay and a fantasy setting with theoretical and computational physics research to deliver an engaging and pedagogically rich experience.
- http://gabrielecirulli.github.io/2048/                       
- http://vinaybajaj2610.github.io/         , 
- https://github.com/RickCarlino/Cosmic-Conquest-1982 - a re-creation of a realtime strategy game published in BYTE Magazine in 1982. It is credited as one of the first realtime strategy computer games.I am going to try to get it running in GForth on modern hardware.
- https://github.com/OpenDUNE/OpenDUNE - an open source re-creation of the popular game "Dune II", originally made by Westwood Studios, and released by Virgin Entertainment. It attempts to re-create the original game and apply modern technology to it to allow it to be run natively on most operating systems. 
- Dune Legacy - an effort by a handful of developers to revitalize the first-ever real-time strategy game. It tries to be as similar as possible to the original gameplay but to integrate user interface features most modern realtime-strategy games have like selecting multiple units
- OpenRA is a Libre/Free Real Time Strategy project that recreates the classic Command & Conquer titles. 
- Mindustry - A sandbox tower-defense game.
- https://github.com/rokups/rbfx - a free lightweight, cross-platform 2D and 3D game engine implemented in C++ and released under the MIT license. Greatly inspired by OGRE and Horde3D.