The hpack Multi-System Archiver is an archiver that was written to
allow the transfer of archived data to different systems.  In the
past archivers have traditionally been available for single systems
only, for example PKZIP and LHARC for the IBM PC, Larc for the
Amiga, StuffIt and Compactor for the Macintosh, and tar and compress
for UNIX systems (while these archivers are available on other
systems, their use is not widespread). Open-keys security included.