PACK condenses text files using a variable-length bit encoding scheme to
create a  binary file  which is  typically 25  to 50%  smaller than  the
original text.  These savings are  only slightly better than half  those
achieved using the  "crunch" and  "spindle" programs, but  on the  other
hand PACK is somewhat  easier to use.  PACKed  files are not  compatible
with SPINDL.  The PACK program supplies its own documentation.