There is only one file type that uses the .WOWPROJ extension:
AddOn Studio Project File
Project file created by AddOn Studio for World of Warcraft (WoW), a program used for developing WoW user interface add-ons; saves the design of the addon as well as a scripted Lua actions for input events; used for saving development progress.
|Addon Studio for World of Warcraft||Free|
Updated: July 18, 2011