Perpetuum is a persistent, sandbox, single server, massively multiplayer sci-fi rpg (MMORPG). Control huge robots and mechs to gain access to an alien planet's resources and knowledge, amass huge wealth, or even claim part of the world for yourself using terraforming and complex infrastructure.

In Star Trek Online, the Star Trek universe appears for the first time on a truly massive scale. Players take the captain's chair as they command their own starship and crew. Explore strange new worlds, seek out new life and new civilizations, and boldly go where no one has gone before.

Anarchy Online – the first ever science fiction MMO – is now on Steam! Compete and cooperate with thousands of players simultaneously on a vast, alien world. Join humanity nearly 30,000 years in the future in a world of perpetual conflict and scientific marvel.

Critically acclaimed and now Free to Play, WildStar is a fantastical sci-fi MMO where you can join your friends or undertake your own epic adventures on the fabled planet Nexus!

8BitMMO is a retro-style 2D massively multiplayer game! It's a giant construction sandbox -- you can build a home or a castle in a persistent streaming world. Found and manage your own city. Fight evil LawyerCats and engage in Player vs Player battle.

Welcome to EverQuest® - the original fantasy MMORPG. Explore huge worlds, fight challenging foes, and grow your character with friends. Discover why players have quested, grouped, and raided in Norrath for more than two decades.

Play ArcheAge - A vast open-world sandbox MMORPG with everything you can possibly imagine.

Aberoth is a fantasy massively multiplayer online role playing game with charming retro graphics and tons of freedom.

CSC is a casual space MMO with fast-paced combat, a robust player economy, and an uncapped crafting system. CSC is a game in active development.

Orake Classic is an old school, 2D tile-based ORPG featuring a variety of skills, monsters, bosses, quests, and extensive lands to explore.

Behold an anime-themed land of wonders, friendship and skill, shrouded in the mysteries of an ancient world yours to explore. Forge relationships and find new friends, take up a job, or soar through the majestic skies as you rediscover a social MMORPG beloved by many around the world!

Albion Online is a fantasy sandbox MMORPG featuring a player-driven economy, classless combat system, and intense PvP battles. Explore a vast open world full of danger and opportunity. Grow your wealth, forge alliances, and leave your mark on the world of Albion.