Quietly one of the most popular games on the net, RuneScape is not exactly short of players. It has, for the longest time, however, been short of a way to provide those players with the same kind of community-building infrastructure as other popular online games. The latest update fixes that, and it's proving popular, as Jagex report: "In just 24 hours more than 250,000 RuneScape players have formed clans, including over 370 clans containing 50 members or more. The update gives RuneScape clans a real presence in the game and included a host of new features including individual clan camps, chat channels, clan customisations, clan websites and new in-game content; Rated Clan Wars."
RuneScape is free to play, and has been out for a very long time indeed.