7-Zip

Commercial software equivalent(s): WinZip, PKZip

Description: File archiver with high compression ratio.

Operating system(s): Windows, Linux

License:  free software distributed under the GNU LGPL (except for the RAR plugin).

Website: http://www.7-zip.org/

Download URL: http://www.7-zip.org/download.html

Documentation/FAQ: http://www.7-zip.org/faq.html