Blizzard, the makers of the massively multiplayer online role-playing game (MMORPG) World of Warcraft has said it has surpassed 5 million customers worldwide.

"World of Warcraft's growth continues to exceed all our expectations", said Mike Morhaime, president and cofounder of Blizzard Entertainment.

With a strong presence across Asia, Australia, Europe, and North America, World of Warcraft has quickly become the world's most popular MMORPG.

Seeing the popularity, the company is set to release an add-on pack in 2006.

World of Warcraft: The Burning Crusade will add new lands, quests, monsters, magic items, spells and abilities, two new player races, a new player profession, ten new levels of power for players to achieve, and much more.

The game was launched last year in America and this year in the UK. It was most recently launched in the regions of Taiwan, Macau, and Hong Kong on November 8, 2005.

In August the company announced that it has reached the 4 million marker.