Stuffit Expander is a program that is capable of undoing most of the encoding / packaging done for downloading / e-mailing. It will work on most flavors of MS-Windows, Mac OS (both X and classic), Linux, and Solaris. It has the ability to unzip, unstuff, ungzip, unbzip, uncompress, uncompact, unarc, unlharc, unrar, uudecode, untar, and disentangle several other processed formats besides.