p7zip is a Unix port of 7-Zip, a file archiver with high compression
ratio (www.7-zip.org) with lots of features:

* 7-Zip is free software distributed under the GNU LGPL
* High compression ratio in new 7z format with LZMA compression
  o Unicode file names
  o Variable dictionary size (up to 4 GB)
  o Compressing speed: about 1 MB/s on 2 GHz CPU
  o Decompressing speed: about 10-20 MB/s on 2 GHz CPU
* Supported formats:
  o Packing / unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
  o Unpacking only: RAR, CAB, ISO, ARJ, LZH, CHM, Z, CPIO, RPM, DEB
    and NSIS
* For ZIP and GZIP formats 7-Zip provides compression ratio that is
  2-10 % better than ratio provided by PKZip and WinZip
* Self-extracting capability for 7z format

WWW: http://p7zip.sourceforge.net/