Technologists have to act as responsible members of society, but they also have to cut themselves out of the loop of ruling the world.
--Tim Berners-Lee

MMORPG

Massive Multiplayer Online Role-Playing Game (MMORPG)

social software with avatars in a virtual reality persistent world, evolved from MUDs and MUSHes

World of Warcraft

Open-ended MMORPGs

Second Life
There
ActiveWorlds
Sims Online