Command-line utilities to:

* create StuffIt (.sit) and Zip (.zip) archives
* encode files into uuencode, BinHex, and MacBinary formats
* expand StuffIt and Zip archives
* expand encrypted StuffIt archives
* decode or expand: Compact Pro, zip, arc, arj, lha (lzh),
  rar, gzip, UNIX compress, uuencode, BinHex, btoa, MIME,
  tar, MacBinary, segmented StuffIt, PrivateFile, bzip2,
  and AppleSingle.

WWW: http://www.stuffit.com/expander/