Here are some interesting things I noticed while writing this program:

The ART format is nowhere near as irritating as the bitmap format...

You know those text screens that are displayed when you exit a game?  It looks like Apogee/3DRealms write over old screens to make their new ones.  Try opening one and saving it as a text file to reveal the "hidden messages" ;-)  (i.e. text with the same foreground and background colour.)  Some of them look like they've been written over a BBS menu screen...

Most file formats are nearly identical.

AlwaysUnloadDll is great...shame it doesn't work for namespace extensions.

Compression and/or encryption sucks.  Unless someone else can tell you how to get around it ;-)