StatBuster is a very simple addon for World of Warcraft, which helps players compare the total stats of any two arbitrary item sets. This becomes useful for simple tasks such as comparing stats of a two-handed weapon with the combined stats of a mainhand and an offhand weapon, but also for more complex tasks such as comparing total stats between two completely different equipment sets.
StatBuster has a single command (well, two), which is /sb (or /stat). This command brings up the main StatBuster frame, in which all the items will be listed and compared.
The frame consists of two item set frames and a comparison frame. The item set frame on the left, labeled 'Original Set', denotes the set to be compared against, and the item set frame on the right, labeled 'Replacement Set', denotes the set to compare with. The comparison frame shows the stats as a simple means of subtracting the stats of the left set from the stats of the right set.
To add items to the left set, simply Shift+LeftClick on any item (or item link). To add items to the right set, use Shift+RightClick. Note that while the StatBuster frame is being displayed, the dressing room feature will not work.