packit

from The Free On-line Dictionary of Computing (8 July 2008)

PackIt

   <file format, tool> A file format used on the {Apple
   Macintosh} to represent collections of Mac files, possibly
   {Huffman} compressed.  Packing many small related files
   together before a {MacBinary} transfer or a translation to
   {BinHex} 4.0 is common practice.

   (1994-11-30)