7z and 7za file archivers with high compression ratio
p7zip is the Unix port of 7-Zip, a file archiver that archives with very high compression ratios.
* /usr/bin/7za a standalone version of the 7-zip tool that handles 7z archives (implementation of the LZMA compression algorithm) and some other formats
* /usr/bin/7z not only does it handle 7z but also ZIP, Zip64, CAB, RAR, ARJ, GZIP, BZIP2, TAR, CPIO, RPM, ISO and DEB archives.
7z compression is 30-50% better than ZIP compression. p7zip provides 7zr, a light version of 7za, and p7zip a gzip like wrapper around 7zr.