What was the first Crossplay game?

What was the first Crossplay game? Final Fantasy XI was the first game to allow gamers across multiple platforms (Xbox 360, PS2 and PC) to play together. It has between 200,000 and 300,000 players logging in every day, and remains the most popular MMORPG in Japan.

Final Fantasy XI was the first game to allow gamers across multiple platforms (Xbox 360, PS2 and PC) to play together. It has between 200,000 and 300,000 players logging in every day, and remains the most popular MMORPG in Japan.