The atool package is a collection of Perl scripts that allows you to handle many different archive formats and compression schemes using a single command-line interface. Atool uses other tools behind the scenes to perform the heavy lifting. With atool, you can handle any archive without having to remember what command-line tool to use to expand it and which options that particular tool expects.
Atool comes with a collection of commands, including aunpack, apack, als, acat, adiff, and arepack. The tools are all links to the main atool Perl script, but they perform the actions that their name suggests -- for example, unpacking or creating a new archive.