First cross-platform online role-playing 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. GWR Video Gamer's Edition 2008, title: First cross-platform online RPG. 27 June 2013: from Lucian Randall - not able to find updated figures for players, although did find a report that said FFXI is the most profitable of the series as of June 2012 (no figures given) but interestingly 'if you add up the total play time of all currently active FFXI players, you'll reach a figure of over 200,000 years' as reported here: http://andriasang.com/con1mt/ffxi_profits/