Best Open Source (Free) Video Games
Open Source games are programs for which the original code has been released, meaning anyone can legally get the code for free, or more importantly, the game itself. This is a list of my favorite open source games, all are free, and most are available across Windows, Mac, and Linux computers.
Urban Terror
Urban Terror is a great multi-player first person shooter with a modern weapons set and unique, game defining movement abilities. A thriving online community and a vast collection of maps allow for endless gaming. Urban Terror’s most unique feature is a slew of new ways of movement such as wall jumping and sliding which makes for very interesting fast-paced action. Instead of watching the whole enemy team run around the same corner the same way, creative players could be coming at you from every direction.
Multiplayer First-Person-Shooter - Windows, Mac, Linux
Nexuiz (Xonotic)
Nexuiz is an fast-paced Deathmatch style shooter with a good selection of weapons, great variety of maps, game types, and gameplay modifications. It includes a singleplayer campaign of bot matches. Recently the name and other parts of Nexuiz have been taken by a game company, so new changes to the Open Source Nexuiz project are under the name Xonotic. The old, unaltered Nexuiz is still available.
Multiplayer, Singleplayer, First-Person-Shooter - Windows, Mac, Linux
Smokin' Guns
Smokin’ Guns is a Western multiplayer shooting game. Players use pistols, shotguns, rifles, and other items to fight it out in western themed maps. Buying weapons and using the map to your advantage, while countering other players’ choices, keeps the game very interesting — we often play on one map for hours. Unfortunately, there are rarely players online, so you have to find your own group to play this great game with.
Multiplayer First-Person-Shooter - Windows, Linux
Jump 'N Bump
Jump ‘n Bump is a simple 2D game in which players control bunnies which attempt to make each other explode by jumping on them. The game controls respond very well and controlled your bunny is simple yet difficult. The whole game depends on out-maneuvering your opponent and using the map to your advantage. Rather than play some difficult and stressful shooter, relax by playing this fun little game with a few friends.
Multiplayer Platformer - Windows, Mac, Linux
GLtroN
Remember those digital motorcycles from Tron? Ever thought it'd be cool if there was a game where you actually drove those lightcycles in 3D? That is exactly what GL-Tron is. Battle with other speeding vehicles as you struggle to avoid hitting their wall-like trails.
Multiplayer Driving Simulator - Windows, Mac, Linux
Liquid War
Liquid War is an abstract take on battle strategy. Though incredibly simple, this game can get very complex when you're trying to win. Control your liquid to surround and engulf the enemy team. It was awarded with "the most original Linux Game". This game is a great way to put your mind up against your friends.
Multiplayer Real-Time-Strategy - Windows, Mac, Linux
Frogatto and Friends
Frogatto and Friends is a recent well-made platformer with smooth controls and a good storyline. Controlling Frogatto is fun while the many different enemies are interesting to fight.
Singleplayer Platformer
Download Frogatto and Friends (website currently unavailable)
TORCS
TORCS is the best open source driving simulator. It has great graphics and realistic driving with plenty of adjustments that can be made. Though I don't usually play realistic driving sims, I had fun speeding through races (in last place) in TORCS.
Singleplayer, Multiplayer Driving Simulator - Windows, Mac, Linux
Bitfighter
Bitfighter is a 2D multi-player space-shooter actively being developed. You fly a fast triangle-spaceship with various weapons and modules and fight other players. There are several game-types that take place in maze-like 2D maps. Skilled players move fast and use specialized weapons and modules to their advantage. It includes a simple map editor.
Multiplayer 2D Space-Shooter - Windows, Mac, Linux
Tremulous
Tremulous is a team-based strategy game where Space-Faring Humans and Hive-Mind Aliens battle in first-person, as well as building bases while destroying their opponent's base. It has the action of a first-person-shooter with the strategy of a real-time-strategy game.
Multiplayer First-Person-Shooter - Windows, Mac, Linux
Sauerbraten
Sauerbraten is a very fast shooter with very nice looking graphics and most computers can run it. Most players play instagib style -- one shot is one kill, but your gun reloads slowly. Capture the flag is fun to play, with fast-moving players trying to dodge shots while moving the flag when only one can kill him. There is a doom-like singleplayer. This game also features an easy to use in-game multiplayer editor, allowing almost any player to create their own maps. Simply making things in the editor with other people is fun in itself.
Multiplayer, Singleplayer First-Person-Shooter - Windows, Mac, Linux
Battle for Wesnoth
Battle for Wesnoth is a very popular turn-based-strategy game. Players recruit and control armies to defeat the enemy leader in a the Tolkien-like land of Wesnoth. There are elves, humans, dwarves, orcs, undead and even dragons. There are plenty of Campaigns of varying difficulty with strong story-lines and well crafted battles. Thanks to the map editor and the in-game addon manager, many more campaigns, maps, and even new races can be added to the game.
Multiplayer, Singleplayer Turn-Based-Strategy - Windows, Mac, Linux
Scorched 3D
Based on the original Scorched Earth, Scorched 3D is a turn based tank game similar to the 3D worms games. Players can move tanks and fire a variety of weapons in an attempt to hit another tank somewhere else on the battlefield. Every explosion blows away the land the environment is made out of, so the battlefield is constantly changed as the battle goes on.
Multiplayer Turn-Based-Shooter - Windows, Mac, Linux