I can't remember whether it's a tar file or a GZ file, and honestly, I don't know the difference between the two.

A .tar file is a container for other files with no compression. A .gz file is a single compressed file. So the two together - a .tar.gz file (or .tgz on silly systems that only allow one extension) offer similar functionality to .zip on Windows. Compression is usually better (especially if the archive contains many small files) but extracting individual files from the archive is more painful.

Displayserver gives you an uncompressed .tar, I believe, since mp3s don't compress much anyway.

Borislav