by Igor Pavlov
7-Zip is a file archiver with high compression ratio.
Packing / unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
Unpacking only: ARJ, CAB, CHM, CPIO, DEB, DMG, HFS, ISO, LZH, LZMA, MSI, NSIS, RAR, RPM, UDF, WIM, XAR and Z.
For ZIP and GZIP formats, 7-Zip provides a compression ratio that is 2-10 % better than the ratio provided by PKZip and WinZip
Pre compiled versions available for multiple Linux distros and Macintosh at the developer's site as well as from p7zip (linux/unix version of 7zip) sourceforge project page