pax

About pax

From Debian's package description

paxtar is an implementation of an archiving utility that reads and writes several formats - traditional ones, the extended formats specified in IEEE 1003.1, and the ar(5) format used by deb(5) packages (MirBSD specific paxtar extension). The pax interface was designed by IEEE 1003.2 as a compromise in the chronic controversy over which of tar or cpio is best, but this implementation offers paxcpio and paxtar for easy calling.

This is the MirBSD paxtar implementation supporting the formats ar, bcpio, cpio, SVR4 cpio with and without CRC, old tar, and ustar, but not the format known as pax yet. It has extensions for removing non-numerical user and group IDs from the archive, storing hardlinked files only once, setting ownership to the superuser, anonymising inode and device information, changing the mtime to zero, and producing GNU tar compatible trailing slashes on ustar directory nodes. Its "ar" format is suitable for operating on *.deb files, unlike that of GNU binutils.

Note that ACLs and Extended Attributes are not supported.

From Debian's description of the pax package, under that package's license.