Hard driveThe only game on the US market that is sold with a PS2 hard drive (40GB). Although more games have plans to use the hard drive (such as Resident Evil: Outbreak), there is currently (as of September 2004) no other way to get the hard drive than to buy the Playstation 2 version of Final Fantasy XI.
MilestonesThe first Final Fantasy game to be exclusively online. Also, coincidentally, the first massively-multiplayer online role-playing game to have a discernible beginning and ending, with a story line that every player can experience at any time.
SalesAlthough wildly popular in the US (with more than 500,000 subscribers as of early 2004), the game was less so in Japan. Square-Enix made a public claim that unless they could get 200,000 Japanese players to sign up and play the game, it would not be exported to the US due to financial failure. The release of the PS2 version shot up in sales enough for US players to get the game.
Version differencesThe Windows base game was only released in Japan. The Xbox 360 version includes the three expansion packs. Both the Windows and the PlayStation 2 version were launched in North America with the first expansion pack Rise of Zilart included. The European Windows version includes the first expansion as well as the second: Chains of Promathia. The game is also provided for free if you buy the 40GB Internal Hard Disk for the PS2.
Information also contributed by Sciere