libarchive1 2.8.4-1ubuntu0.11.04.1 (i386 binary) in ubuntu natty

 The libarchive library provides a flexible interface for reading and
 writing streaming archive files such as tar and cpio. The library is
 inherently stream-oriented; readers serially iterate through the archive,
 writers serially add things to the archive. In particular, note that
 there is no built-in support for random access nor for in-place
 modification.
 .
 libarchive can read at least five tar formats, four cpio formats,
 ISO9660 CD/DVD images (including RockRidge extensions), and ZIP
 files.
 .
 libarchive can write two tar formats (ustar and pax), one cpio format
 (odc/POSIX), and two types of shar files (with and without uuencoding).
 .
 The bsdtar Debian package, which is the default tar(1) on FreeBSD,
 is built using libarchive.
 .
 There is also a manpage, tar(5), that provides an excellent description
 of the various tar file formats.