How much more free can a game get, than free in price? Off course “DRM-free and open source” is the correct answer. Look what I have found for you.

Just like Firefox and other open source projects, there are game developers who let you access their code. Mostly these games are hobby projects and free in its price as well. A lot are outdated, abandoned, forgotten, but there are also some pleasing titles to be found as well, even a few impressive active projects. I took the time to look up in the web for the interesting ones and created this list. Have in mind that I didn’t play most of these games and I cannot judge them.

If you are a Windows user, then you can usually download an executable file from the download sector on the Website. The Linux user can lookup in the repository of their distribution. If it is not there, then either the website provides a pre compiled executable or you can lookup on the various places I linked. Just make sure you get the newest version, as not all sources are up to date.

What is Open Source?

Open source means the source code of a project is accessible to others than the developer, usually to the public. In general this allows the examination or modification of the programs code and rebuilding it on different computer systems. The license of the code or included proprietary media files can grant or limit specific rights and freedom, like distribution for in example. In this article I don’t make a distinction between truly free software and open source content.

40 GAMES

Most, but not all of the games in this list are sort of inspired by, re-imagination or even clones of popular games. Have in mind a few are not developed anymore, progress is slow and unfinished. This can be a problem with multiplayer modes, where only a handful or no one is playing. Sometimes the decision to include a specific title wasn’t easy, but even a dead project can be enjoyable today; if the underlying composition is good. With that it mind, have fun with the exploration.

Overview

A little compact list of all titles from the list below. The links point directly to the websites: 0 A.D., The Battle for Wesnoth, Blobwars: Metal Blob Solid, Chromium B.S.U., Dungeon Crawl Stone Soup, Endless Sky, FlightGear, Freeciv, Freedoom, FreedroidRPG, Frets on Fire, Frozen Bubble, Gravity Bone, Hedgewars, Mari0, Minetest, Nethack, Neverball, Oolite, OpenArena, OpenSurge, Pingus, Pioneer, The Secret Chronicles of Dr. M, Spelunky Classic, Super Tux, SuperTuxKart, Stunt Rally, Taisai Project, Tales of Maj’Eyal, Teeworlds, The Dark Mod, TORCS, Warfork, Warzone 2100, Widelands, Wizznic, Wyrmsun, Xonotic, Zero-K

0 A.D.

Battle for Wesnoth, The

Blobwars: Metal Blob Solid

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: 2D Action platformer Similar To: –

Chromium B.S.U.

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Vertical arcade bullet hell shmup Similar To: –

Dungeon Crawl Stone Soup

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Roguelike dungeon crawler Similar To: Linley’s Dungeon Crawl

Endless Sky

FlightGear

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Flight simulator Similar To: Microsofts flight simulator

Freeciv

Freedoom

FreedroidRPG

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Isometric rpg Similar To: Diablo / Paradroid

Frets on Fire

Frozen Bubble

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Match block puzzle Similar To: Puzzle Bobble

Gravity Bone

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: First person adventure Similar To: –

Hedgewars

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Turn based tactical artillery battle Similar To: Worms

Mari0

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Jump & Run + Puzzle Similar To: Super Mario Bros. + Portal

Minetest

Nethack

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Terminal roguelike dungeon crawler Similar To: Hack / Rogue

Neverball

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: 3D action-sport dexterity Similar To: Super Monkey Ball

Oolite

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Space trading and combat simulator Similar To: ELITE

OpenArena

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Multiplayer first person shooter Similar To: Quake 3 Arena

OpenSurge

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Jump & Run Similar To: Sonic

Pingus

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Realtime puzzle Similar To: Lemmings

Pioneer

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Space adventure simulator Similar To: Frontier: Elite 2

Secret Chronicles of Dr. M, The

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Jump & Run Similar To: Secret Maryo Chronicles / Super Mario Bros.

Spelunky Classic

Website

Linux Flathub

Linux Snapcraft

Linux Lutris (look for classic)

Steam

YouTube

Reddit Genre: Roguelike dungeon platformer Similar To: La-Mulana / Spelunker

Super Tux

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Jump & Run Similar To: Super Mario Bros.

SuperTuxKart

Stunt Rally

Taisai Project

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Vertical bullet hell shmup Similar To: Touhou series

Tales of Maj’Eyal

Teeworlds

The Dark Mod

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: First person stealth Similar To: Thief series

TORCS

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Racing simulation + AI programming Similar To: RARS

Warfork

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: First person arena shooter Similar To: Quake / Warsow

Warzone 2100

Widelands

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Realtime strategy building Similar To: Settler 2

Wizznic

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Puzzle Similar To: Puzznic

Wyrmsun

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Realtime strategy Similar To: Warcraft 2

Xonotic

Zero-K

Website

Linux Flathub

Linux Snapcraft

Linux Lutris

Steam

YouTube

Reddit Genre: Realtime strategy Similar To: Total Annihilation

More

A lot didn’t make into this list for various reasons. First and foremost the ZDOOM engine, which is a port of the original DOOM to modern PCs. It is not just a game, but a whole engine to load up other games. This tool is so powerful, it allows for easy modification and creation of new games.

Then there are new projects, which only works if you have the original game files of an old commercial classic, in example:

Honorable mentions, partly through community recommendations:

My main sources for the research was:

There are off course a lot more, but I leave it here to you. If you want, leave me a comment with recommendations. But I want to stay at 40 games in the list and probably won’t include anymore. The more people know about a specific project, the more history and credibility the devs have, the more I am interested into. Easy installation process on Linux and Windows are big plus too.