World Of Warcraft.

World of Warcraft (WoW) is a massively multiplayer online role-playing game (MMORPG) by Blizzard Entertainment. It is the fourth released game set in the fantasy Warcraft universe, which was first introduced by Warcraft: Orcs & Humans in 1994.^[5] World of Warcraft takes place within the Warcraft world of Azeroth, approximately four years after the events at the conclusion of Blizzard's previous Warcraft release,Warcraft III: The Frozen Throne.^[6] Blizzard Entertainment announced World of Warcraft on September 2, 2001.^[7] The game was released on November 23, 2004, on the 10th anniversary of the Warcraft franchise.

The first expansion set of the game, The Burning Crusade, was released on January 16, 2007.^[8] The second expansion set, Wrath of the Lich King, was released on November 13, 2008.^[9] 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, though the developers did not yet know what it would be about.^[10]

With 11.1 million subscribers as of June 2011,^[11] World of Warcraft is currently the world's most-subscribed MMORPG,^[9][12][13] and holds the Guinness World Record for the most popular MMORPG by subscribers.^{[14][15][16][17]}