Vying Games is an asynchronous, online game system. Games are played in a web browser, one turn at a time, which could take days or weeks, depending on the game and how often the players take their turns. If both players are online at the same time, polling allows near-realtime play.
Vying Games also provides computer opponents of varying degrees of difficulty. Vying is on "hiatus" for over a month now (as of January 1, 2013). The web site is probably defunct.