Wikia

WoW Model Viewer is a program that allows users to see all the models for characters, armor, weapons, monsters, and spell graphics in the game files. Additionally, it enables people to take screenshots, add backgrounds, and add weapons/armor to a character of one's choice.

The latest official version (v0.5.08) by the original author John Steele (aka Darjk) and chuanhsing was released on March 15th, 2010. With this version, all files up to Patch 3.3.3 can be viewed.

WMVs are widely used by machinimists with the "blue- (or green-)screen-effect", because there are less limits there than in the real game.