Free / open source games: S - U

There are more and more free / open source games: this list, far from being exhaustive but continuously growing, gives priority to projects that keep on being developed and is meant to help whoever is looking for some fun.

All these open source games are free but remember that the term free is meant as in "free speech", not as in "free beer" so if you like one of these games please try to contribute to its development: some teams need varioul kinds of help (programmers, graphics experts...), some accepts donations to finance the development of a game, some need help to test new versions which means that you can have fun and at the same time help the development of a project.

This is the sixth part of the list and included the games from S to U: from the side menu you can access to all the other parts of the list.

Sauerbraten, also known as Cube 2 because it's derived from the game Cube (now abandone but still available), is a Quake style 3D FPS with single player and multiplayer modes.

A review of the game is available.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 2020 Edition (December 21 2020)

Hardware/software requirements: 1 GHz CPU, 256 MB RAM, graphics card with 3D acceleration

Scid ("Shane's Chess Information Database") is a chess database application. You can maintain a database of chess games, search games by many criteria, view graphical trends, and produce printable reports on players and openings. You can also play against various engines, or on Internet (FICS).

Operating systems: Windows, Linux, Mac OS X

Latest Version: 4.0 (September 1 2009)

Scid Vs PC is a usability and bug-fix fork of Scid. With it you can play chess online or against the computer, browse tournaments downloaded in pgn format, and create huge chess databases

Operating systems: Windows, Linux, Mac OS X

Latest Version: 4.13 (October 25 2014)

Scorched 3D is inspired to the classic game "Scorched Earth". Various factions on one of the existing maps take turn at shooting at each other using various weapons that require various aiming skills while the opponent must use his skills to defend his faction.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 43.3 (February 6 2012)

Hardware/software requirements: 500 MHz CPU, 128 MB RAM, 200 MB hard disk, graphics card with 3D acceleration

SDL Asylum is a free version of old game Asylum. The player must enter a sick mind to shut down malfunctioning brain cells.

Operating systems: Windows, Linux, FreeBSD, Haiku OS

Latest Version: 0.3.2 (17/08/2009)

Hardware/software requirements: graphics card with 3D acceleration

Search and Rescue is a flight simulator where the player is given a series of missions in which they are tasked with searching for and picking up people in need of help. There is also a Free Flight mode in which the player can select an aircraft and fly around without any objectives.

Sistemi operativi: Linux

Ultima versione: 1.4.0 (August 7 2011)

Hardware/software requirements: graphics card with 3D acceleration

Secret Maryo Chronicles is inspired to the classic game "Super Mario" for the fans of old 2D run and jump games.

Operating systems: Windows, Linux, Mac OS

Latest Version: 1.9 (August 17 2009)

Simsu is a basic Sudoku game. You can switch between filling in notes (pencil mode), or filling in answers (pen mode). To make it easier to see where to place numbers, you can highlight all instances of a number. You can also check your answers for correctness while playing.

Operating systems: Windows, Linux,  Mac OS

Latest Version:  1.2.1 (March 30 2009)

Your goal is to establish a successful transport company. Transport passengers, mail and goods by rail, road, ship, and even air. Interconnect districts, cities, public buildings, industries and tourist attractions by buiding a transport network you always dreamed of.

Planes, ships, trains, trams, trucks, busses and monorails are at your disposal. You can control and watch your finances and the traffic of your vehicles and goods.

You can play as long as you like. Start in 1880 and finish in 2050. There will be new vehicles and buildings throughout this time. Cities will grow and merge forming metropolises.

Play against the AI or on your own. Only if you are in debt for three months, you are bankrupt and the game is over.

Operating systems: Windows, Linux, BeOS, MAC OS X, other operating systems supported by the game library Allegro

Latest Version: 112.3 (May 26 2013)

Hardware/software requirements: graphics card with 3D acceleration, Allegro game library for the versions based on it

Smash Battle is a fast, old skool, 2D, platform, shoot ‘m up action based on the famous Mario battle from Super Mario Bros 3. Fight your way through several missions to unlock secret characters.

Operating systems: Windows, Linux

Latest Version: 110224 (February 24 2011)

Smokin' Guns is intended to be a semi-realistic simulation of the "Old West's" great atmosphere and was developed on Id Software's Quake III Arena Engine. This includes duels and bank robberies using only weapons with historically correct design.

Operating systems: Windows, Linux

Latest Version: 1.0 (January 1 2009)

Hardware/software requirements: graphics card with 3D acceleration

Sokobano is a Sokoban game featuring nice 3D graphics.

Operating systems: all the ones with Java support

Latest Version: 1.0.3 (April 9 2010)

Hardware/software requirements: Java RE 6 or above, graphics card with 3D acceleration

SourGumdropK is an implementation of the game Kakuro in its Cross Sums version.

Operating systems: all the ones with Python 2.6 support and the Tkinter library

Latest Version: 1.0.4 (January 12 2010)

Hardware/software requirements: Python 2.6 and Tkinter library

Spacemax è is an arcade game Space Invaders style.

Operating systems: all the ones with Python and Pygame support

Latest Version: 7.2 (August 1 2011)

Hardware/software requirements: Python and Pygame

SpaceZero is a 2D space combat, multiplayer (two players by now) net game. The objective is to conquest the space, defeating all enemies. At starting point you have only one ship and one planet, but you have money to buy more ships to conquest more planets.

Operating systems: Linux

Latest Version: 0.86.00 (December 21 2013)

Speed Dreams is a car race simulator derived from T.O.R.C.S. with many car models and circuits.

Operating systems: Windows, Linux, Mac OS X, FreeBSD, Solaris

Latest Version: 1.4.0 (April 5 2010)

Hardware/software requirements: 500 MHz CPU, 128 MB RAM, graphics card with 3D acceleration

Spring is more than a game: it's a project to develop an engine to create real-time strategy games with huge 3D battle and different viewing angles. Various games are available with settings that go from the classic World War II to science fiction ones, including the ones inspired to Star Wars or Gundam.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 101.0 (February 28 2016)

Hardware/software requirements: 1 GHz CPU, 512 MB RAM, 200 MB hard disk, graphics card with 3D acceleration and 64 MB of memory

Stellar Forces is a squad-level, turn based multi-player strategy game. Imagine Laser Squad or X-Com missions being multi-player across the internet. Each player controls a squad of units and takes their turn using the client software to complete their mission and defeat their opponent. There are multiple missions available, as well as lots of different kinds of weapons and equipment.

Operating systems: all the ones with Java support

Latest Version: 1.65 (March 21 2011)

Hardware/software requirements: Java

Stendhal is a MMORPG based on open source framework Arianne where the player can develop his fictional character in a fantastic world exploring, trading and living many adventures.

Operating systems: Windows, Linux, Mac OS X, FreeBSD, Solaris

Latest Version: 1.14 (June 2 2014)

Stunt Rally is a car simulation game based on VDrift.

Operating systems: Windows, Linux

Latest Version: 2.5 (September 21 2015)

Hardware/software requirements: graphics card with 3D acceleration

Sudokuki is a graphical SUDOKU game. It solves even the most difficult sudoku grids for you. It can generate a sudoku, play sudoku, and print a sudoku.

Operating systems: all the ones with Java support

Latest Version: 1.2.2 (April 6 2014)

Hardware/software requirements: Java

Summoning Wars is an action RPG with point-and-click fight system. Choose from 4 Classes with 24 unique abilities each and jump into a campaign playable in both single and multiplayer mode. Multiplayer mode is usable by up to 8 players. There are hundreds of items to collect and dozens of monster types to fight. Meet citizens and sinister puppet-masters with secrets of their own and trade with well-equiped traders - or search for the blackmarket and stock enchanted items.

Operating systems: Windows, Linux

Latest Version: 0.5.6 (March 4 2012)

Super Methane Brothers is a conversion of the Commodore Amiga game. Trap baddies in a gas cloud. Suck into your gas gun. Throw against a wall to destroy them.

Operating systems: Windows, Linux

Latest Version: 1.5.0 (October 22 2009)

SuperTux è is a free video game strongly inspired to the original Super Mario games.

Operating systems: Windows, Linux, MacOS X

Latest Version: 0.6.0 (December 23 2018)

SuperTuxKart is a kart racing game with many tracks.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 1.4 (November 1 2022)

Hardware/software requirements: graphics card with 3D acceleration

Tales of Maj’Eyal (ToME) is a free, open source roguelike RPG, featuring tactical turn-based combat and advanced character building. Play as one of many unique races and classes in the lore-filled world of Eyal, exploring random dungeons, facing challenging battles, and developing characters with your own tailored mix of abilities and powers.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 1.0.0 (December 31 2012)

Tanglet is a single player word finding game based on Boggle. The object of the game is to list as many words as you can before the time runs out. Every time you find a new word, you are given more time. Each word must be at least three letters long.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 1.2.1 (February 1 2012)

Teeworlds is a free online multiplayer game, available for all major operating systems. Battle with up to 16 players in a variety of game modes, including Team Deathmatch and Capture The Flag.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 0.6.2 (May 1 2013)

Tesseract is a first-person shooter game focused on instagib deathmatch and capture-the-flag gameplay as well as cooperative in-game map editing.

Operating systems: Windows, Linux, Mac OS X

Latest Version: First Edition (May 11 2014)

Hardware/software requirements: graphics card with 3D acceleration

Tetzle is a jigsaw puzzle game that uses tetrominoes for the pieces. Any image can be imported and used to create puzzles with a wide range of sizes. Games are saved automatically, and you can select between currently in progress games.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 2.0.0 (May 18 2011)

Hardware/software requirements: graphics card with 3D acceleration

T.O.R.C.S., meaning The Open Racing Car Simulator, is a car race simulator with many car models and circuits.

Operating systems: Windows, Linux, Mac OS X, FreeBSD

Latest Version: 1.3.6 (April 24 2014)

Hardware/software requirements: 500 MHz CPU, 128 MB RAM, graphics card with 3D acceleration

Tower Toppler (aka Nebulous) is the reimplementation an old 'jump and run' game. In this game you have to climb to the top of a tower avoiding all kinds of creatures that want to push you down.

Operating systems: Windows, Linux, Unix, Windows, BeOS

Latest Version: 1.1.6 (December 22 2012)

toycars is a race fighting car game. Select human or computer toys. Select track and toy to race. Screen off the toys or item smash them to win a point. Win enough points to win the race. Max 4 human players, 8 total.

Operating systems: Linux, Unix

Latest Version: 1.0.14 (May 20 2013)

Tremulous is a 3D FPS born as and evolution of Quake III Arena taking some features from real-time strategy games: as a result in this very multiplayer oriented game two teams, one of humans and one of aliens, fight each other with a certain set of weapons for each faction.

Operating systems: Windows, Linux, Mac OS X, FreeBSD

Latest Version: 1.1.0 (March 31 2006)

Hardware/software requirements: 700 MHz CPU, 256 MB RAM, 125 MB hard disk, graphics card with 3D acceleration

Trepidation is a 3D FPS based on the Quake III graphic engine with new weapons, maps and vehicles in a war between humans, two post-humans races and cyborgs.

Operating systems: Windows, Linux,  Mac OS X

Latest Version:  Build 072107 (July 21 2007)

Hardware/software requirements: 1 GHz CPU, 512 MB RAM, graphics card with 3D acceleration

Tric-Tac-Toe is a variation of the classic game Tic-tac-toe that is played on a 3D board resembling a Rubik's Cube by three players.

Operating systems: Windows, Linux

Latest Version: 0.6.1 (June 11 2009)

Hardware/software requirements: graphics card with 3D acceleration

Triplane Classic is a side-scrolling dogfighting game featuring solo missions and multiplayer mode with up to four players. It is a port of the original Triplane Turmoil game for DOS and aims to match the original game exactly so that high scores remain comparable to the original.

Operating systems: Linux, FreeBSD

Latest Version: 1.0.7 (September 1 2011)

TripleA is a turn based strategy game engine inspired to Axis & Allies.

Operating systems: Linux, Mac OS X, Windows

Latest Version: 1.6.1.4 (December 22 2012)

Hardware/software requirement: Java 1.6 or higher

Tubularix is a game similar to Tetris seen from a tubular perspective.

Operating systems: Linux, Mac OS X, Windows

Latest Version: 0.5.1.7 (June 17 2011)

Tuty-Fruty Slot is simple non gambling slot machine game.

Operating systems: Linux

Latest Version: 23Jun2009 (June 23 2009)

UFO2000 is free and opensource turn based tactical squad simulation multiplayer game. It is heavily inspired by the famous X-COM: UFO Defense game. UFO2000 engine was specifically designed to be compatible with the graphics resources and maps from X-COM.

Operating systems: Windows, Linux, Mac OS X, FreeBSD

Latest Version: 0.9.1176 beta (March 5 2012)

UFO: Alien Invasion is a strategy game where a group of aliens tries to infiltrate Earth while a group of humans handles the planetary defense. In Geoscape mode, the game is about base management and strategy. In Tactical mode, the game is about taking command of your team in various missions to combat aliens wherever they might appear.

Operating systems: Windows, Linux, Mac OS X

Latest version: 2.3.1 (November 29 2010)

Hardware/software requirements: 500 MHz CPU, 128 MB RAM, graphics card with 3D acceleration and at least 32 MB RAM

Ultimate Zombie Fighters is a top-down 2d zombie shooting game. The aim is to survive as long as possible. Zombies will try to break in through windows and try to get you. Kill them and repair the windows to stay alive.

Operating systems: Windows, Linux, Mac OS X, FreeBSD, Solaris

Latest version: 0.1.3 (August 9 2010)

Unknown Horizons is a realtime economy simulation game with strategy elements derived from OpenAnno.

Operating systems: Windows, Linux

Latest Version: 2011.3 (November 11 2011)

Unvanquished is a free, open-source first-person shooter derived from Tremulous but with a new graphics engines and other changes that are making it more and more different from its "parent" game. It combines real-time strategy elements with a futuristic, sci-fi setting.

Operating systems: Windows, Linux, Mac OS X

Latest Version: 0.54 (January 29 2023)

Hardware/software requirements: 1 GHz CPU, 512 MB RAM, 1 GB hard disk, graphics card with 3D acceleration

Urban Terror is a shoot-em-up born as a series of Quake III Arena maps to become a "total conversion" and eventually a standalone game which now is based on a graphic engine derived from the Quake III Arena one.

Urban Terror has an urban gerrilla setting with weapons that reproduce real ones to have the best possible realism.

Operating systems: Windows, Linux, Mac OS X

Latest version: 4.2.021 (November 15 2014)

Hardware/software requirements: 2 GHz CPU, 512 MB RAM, 100 MB hard disk, graphics card with 3D acceleration and at least 128 MB RAM