The Unarchiver – Replacement for Built-in unarchiver in OS X
The Unarchiver is a much more capable replacement for “BOMArchiveHelper.app“, the built-in archive unpacker program in Mac OS X. The Unarchiver is designed to handle many more formats than BOMArchiveHelper, and to better fit in with the design of the Finder.
It is very simple to use and install – simply copy it into your Applications folder or wherever you prefer, and then set archive filetypes to open using it. This can either be done the usual way, or by double-clicking the icon to show The Unarchiver’s preferences.
Supported file formats include Zip, Tar-GZip, Tar-BZip2, RAR, 7-zip, LhA, StuffIt and many other more and less obscure formats.