How do I unpack stuffit files on a unix system?

PackIt II was released in early 1986 and added Huffman encoding. However the encoding was applied after the file had already been "grouped" together, meaning that the compressor had to work on the file as a whole, or not at all. Since Mac files often consisted of text in the data fork and binary data in the resource fork, compressing these separately and then joining them together would likely offer better compression overall. PackIt III, released in mid-1986, added DES encryption. According to Chesley this option was not widely used, but nevertheless PackIt III became the de-facto standard compression/archiving system on the Mac through this period. In December 1986 he joined Apple Computer, and work on PackIt ended.