The contents of Borderlands game data files can be extracted, revealing generic UE3 datafiles as well as the two interesting media types, SoundNodeWave and TextureMovie files.
More work has been done, but not yet added here, in a similar steam thread.
All files can be extracted with the use of Unreal Package Extractor.
Drag the .upk you want to extract onto extract.exe and it will be unpacked into a named folder where the upk is located.
In Windows Vista or 7, you may need to copy the .upk file to be extracted out of 'Program Files' into an area unprotected by UAC to successfully extract the files.
Unpacking audio files
The music files are stored in aforementioned SoundNodeWave format files, but can be extracted using OGGExtract in the same method as the other files. Any ogg files found will be extracted to the directory where the upk file was.
Alternatively, you can use a modified OGGExtract. The only difference is that all ogg files will be extracted with their packaged name instead of a generic one. This can be useful for finding specific clips in large files.
OGG files can be played with most common music players, or simply VLC.
Unpacking video files
Currently requires using a hex editor to find the bik data inside of TextureMovie files.
All packages are located in:
Packages\Audio\Music_WAV.upk Packages\Audio\Music_WAV2.upk Packages\Audio\E3_Temp_Assets.upk
Sample extracted media
There is an unused trailer featuring a 60s song, Greenfields:
As well as 20+ minutes of unused dialog and music: <youtube>-MOVIgtStGs</youtube>
Make a shortcut to your executable. Right click for properties and add "-editor" (without quotes) to the command line. Rename the shortcut to (anything) something like Borderlands Editor.
- Note - the editor is hellishly unstable so don't be surprised when it crashes (often).