DLL's?
They are dynamic-link libraries. Executables use them as extension libraries. They can contain executable code or data, but getting it to be viewed in any practical way (without the executable that is planned to use that library) is out of my understanding since the files themselves are compiled from some source, so effectively they are in binary format... so you'd need some kind of decompiler to get the source files out (in some form), and... that's really something of a black art AFAIK. Kinda like nechromancy, reviving bits and bytes from their post-compiling part of life... please be considerate of the poor buggers.
And, what would you see in there that would be of any practical value for you? DLL's are rarely used as containers for game media anyway. I've actually never heard of it but I guess it could be done, although I can't think of anyone wanting to do that for a game.
