Viewing Blizzard's interface code

Downloading interface data
Blizzard has provided an official, but not necessarily up-to-date, mirror
 * http://us.blizzard.com/support/article.xml?locale=en_US&articleId=21466

Extracting interface data
Since the switch to the streaming download system in patch 4.0.1, the previously-used Interface Toolkit is no longer supported by Blizzard. Instead, the interface data and artwork can be extracted directly from the client (as of patch 4.0.6) by using the following console commands to extract the code and art, respectively. 

ExportInterfaceFiles code ExportInterfaceFiles art

Once extracted, the files can be found in the BlizzardInterfaceCode directory where the WoW executable file can be found. Note that this must be done in the actual console (accessed by starting WoW with the  flag, then hitting ), and not via a   slash command.

Also note that the ExportInterfaceFiles command only works from the login screen (and maybe the character selection screen). Once you're in the game, it no longer works and you will just get an "Unknown Command" response.

Interface scripts are best viewed with a Lua editor. To view .BLP files, use a BLP viewer like XnView

Viewing interface data on the web
There are several ways to view the Blizzard interface code online
 * Tekkub's Git repository
 * FrameXML browser
 * Wowprogramming's FrameXML browser