One of the biggest and most popular "virtual worlds" around. Gaia Online is a community-based site rather than an MMORPG, as any "combat" that takes place there is limited to areas that have been set up for player-versus-player games. The players get their own cutesy chibi anime avatars, and they purchase virtual items to dress up these avatars. A lot of VR sites are into this type of thing these days. Gaia Online is noted for making a very strong attempt to maintain a "family friendly" PG-13-or- less level for all of its players, all the time.
Gaia Online is huge – probably because of its family-friendly policy – with a membership ranging in the millions. It's so popular that Gaia Online cards are now selling at Target for $10 and $25.
Unlike a lot of other MMORPGs, Gaia Online has a peculiar rivalry going on with 4chan. Because its popularity rivals that of 4chan – and because it represents the complete opposite of the raunchy free-for-all anarchy of the chan boards – Gaia Online has found itself the target of 4chan's ire and wrath more than once. 4chan has "raided" Gaia several times in the past, and its users have attempted to bring down Gaia on several occasions.
In spring of 2008, Gaia threw down the gauntlet by adopted a number of 4chan's favorite memes and making cutesy items available for its users to dress up their avatars. Gaia players can now get their very own Longcat, an "Epic Fail Guy mask" (a.k.a. the ANONYMOUS Guy Fawkes mask), an "om nom nom" hat, and other 4chan memes. When /b/ found out about this (within hours of their introduction on Gaia), they threw a HUGE temper tantrum. The harpoons were and declarations of war against Gaia were issued. However, the worst that /b/ could throw at Gaia were some DDOS attacks – because most of the "serious" users of 4chan realized what a joke this "war" was. Gaia handled the attacks, and as of 2008 they have not backed down.