What is the most popular MMO game that has an out-of-game API
<p>World of Warcraft is off the table, because of the "WOW Glider Lawsuit" of 2008. Also see: <a href="http://stackoverflow.com/questions/4473851/where-is-blizzards-official-world-of-warcraft-api">Where is Blizzards official World of Warcraft API?</a></p>

<p>But, what is the most popular (in terms of usership) MMO Game that does allow programmers to develop out-of-game things (like an Android app).</p>
