World of Warcraft is a massively multiplayer online role-playing game (MMORPG) by Blizzard Entertainment, a subsidiary of Activision Blizzard. The first expansion set of the game, The Burning Crusade, was released on January 16, 2007. The second expansion set, Wrath of the Lich King, was released on November 13, 2008.The third expansion set, Cataclysm, was released on December 7, 2010. At BlizzCon in October 2010, lead producer J. Allen Brack announced that there would be a fourth expansion set for the game, even though the developers don't yet know what it will be about. With 11.4 million subscribers as of March 2011, World of Warcraft is currently the world's most-subscribed MMORPG, and holds the Guinness World Record for the most popular MMORPG by subscribers.
