Source : Free On-Line Dictionary of Computing

Stuffit
     
         (filename extension: .sit) A file
        {archiving} and {compression} utility, developed by {Aladdin
        Systems, Inc.}.  Stuffit was originally developed for the
        {Macintosh} and is still the Mac standard tool for compression
        and archiving (compressing multiple files into one).  Stuffit
        is now also available for {Microsoft Windows} and {Linux}.
        Compared to the standard Windows tool, {WinZip}, it is faster
        and gives better compression.
     
        Stuffit archives can be extracted with Stuffit Expander.
     
        {Stuffit Home (http://www.stuffit.com/)}.
     
        (2003-09-20)