World of Warcraft (often abbreviated WoW) is Blizzard's first MMORPG (Massively Multiplayer Online Roleplaying Game) and takes its starting point from the company's world-renowned Warcraft universe. In World of Warcraft, the war between The Alliance (Alliancen) and The Horde (Horden) has developed in such a way that its original cause has been forgotten. Now the battles continue as a struggle for survival. The game's graphical world is characterized by incredibly varied landscapes, and it also seems to provide fertile ground for different worldviews depending on which race you have chosen and where you start. It is said that when the game reached its peak number of players, it had about 12 million players. The Burning Crusade: On October 28, 2005, Blizzard revealed that the first expansion for the game would be World of Warcraft: The Burning Crusade. This would raise the previous maximum level from 60 to 70 and would also include a new profession (jewelcrafting), the ability to socket jewels into certain items to improve them (this feature stems from Diablo 2), and two new playable races. These new races are for the Horde Blood elves (Blodelvere), who reside in the capital city Silvermoon City, and for the Alliance the so-called Draenei, who reside in the capital Exodar. The expansion also includes Outland as a new playable area, as well as flying "mounts" that can be used in Outland for high-level players (level 70 or, if you are a druid, you can obtain flying form also when you reach level 70). Some of the expansion's innovations will be available to all players, while the most significant expansions, such as visits to Outland and the two new races, will be limited to users who purchase and install the Burning Crusade expansion. On July 21, Blizzard revealed that the new races would be able to use classes that had previously only been available to races in the rival faction, and that blood elves as the sole race in the game would not be able to use the warrior class. These changes caused mixed reactions. It was later changed in the expansion Cataclysm. The expansion pack was released January 17, 2007.