The Free Software Foundation's "tar" tape archiver.

GNU tar saves many files together into a single tape or disk archive,
and can restore individual files from the archive.  It includes
multivolume support, the ability to archive sparse files, automatic
archive compression/decompression, remote archives and special
features that allow tar to be used for incremental and full backups.
This distribution also includes rmt, the remote tape server.

Note that this port will install these utilities with a 'g' prefix,
e.g. gtar, but the texinfo documentation will refer to them without
the 'g' prefix.
