Though I'd been in the game business for a while, MetaSquares was my first online game, and therefore my first real experience with creating virtual communities.
While the majority of virtual communities at that time were either dry and stuffy or tawdry and meaningless, we managed to build a space that was warm and inviting, constantly alive with bright minds and good cheer.
The game itself was an original, designed by Scott Kim, a two player strategy board game with simple rules and deep strategy.
It had a good run on AOL, but eventually succumbed to their changing business models. There was briefly an iOS version, but that no longer exists either. There are a couple of knockoffs, though:
MetaSquares in Flash
Japan Chess Board Game for Android