This add on makes it possible for Linux users to change the Video Options in-game. This is done by killing off the following function(s):
Since there is a lot of confusion around it. The change in version 4 enables you to change the resolution. "Back in the days" WoW would crash regardless, but now wine can change resolution and most of the other settings even without this add-on. The chance of it crashing is still rather high without it tho'.
People who play under Windows have no use for this add-on.