Runescape Great free massively multiplayer online roleplay game. Create your own character and build up your skills, fight monsters and go on quests.

Travian Free mmog similar to Settlers and Civilisation played entirely through your web browser

Galactic Conquest Free MMOG space conquest game inspired by Masters of Orion

Planeshift Free and open source massively multiplayer online role play game

Legends Free multiplayer first person shooter set in large outdoor landscapes where air superiority reigns.

Savage 2:A Tortured Soul A free first person strategic role play game

Nexuiz Mulitplayer deathmatch at it's finest based on ID Software's Quake 1 engine which was opened up for free

Tremulous Free first person shooter with strategy element

America's Army Free first person army simulator

Wolfenstein: Enemy Territory Free World War 2 Team Based First Person Shooter

WarRock A free online multiplayer modern tactical combat FPS

Alien Arena Free multiplayer first person shooter

World of Padman Free colourful first person shooter

The Battle for Wesnoth Free turn based fantasy strategy game.

Advanced Strategic Command Free futuristic turn based strategy game

FreeCiv Free Civilisation style turn based strategy game

Scorched 3D Free 3D turn based strategy like Worms

Crimson Fields Free turn based strategy game

Warmux Free Worms like strategy game with open source mascots

Pingus Free Lemmings like strategy game with penguins

UFO:Alien Invasion A free squad based tactical strategy game

Glest Free 3D realtime strategy game

Free Orion Free turn based galactic conquest game

Vegastrike Space trading and combat simulator

OpenCity Opensource SimCity style city simulation program

Widelands Free Settlers style of game

Simutrans Free transport management simulation

LinCity NG Free SimCity™ style game

Soviet Unterzögersdorf Free point and click adventure game set in a fictitional soviet state.

Frozen Bubble Bright and colourful colour matching game

Neverball Guide a ball around a 3d landscape within a timelimit

Invasion3D Free modern version of the old space invaders game

PowerManga Free vertical scrolling shoot 'em up

Thunder&Lightning Free arcade action flight simulator

Babo Violent 2 Free top down shooter

Foobillard A free snooker and pool game

Racer Free realistic racing simulator

Danger From the Deep Free WWII Submarine Simulator (subsim)

FlightGear Free flight simulator

Exult Game engine to play Ultima 7

ZeldaClassic ZeldaClassic tribute to The Legend of Zelda

The Goonies Free remake of an old 8 bit game

PokerTH Free Poker game featuring network/internet play