7-Zip - is an open source file archiver. 7-Zip operates with the 7z archive format, but can read and write several other archive formats. The program can be used from a command line interface, graphical user interface, or with a window-based shell integration. 7-Zip began in 1999 and is actively developed by Igor Pavlov. The cross-platform version of the command line utility, p7zip, is also available.
7-Zip is open source software. Most of the source code is under the GNU LGPL license. The unRAR code is under a mixed license: GNU LGPL + unRAR restrictions.
7-Zip won several awards, including the SourceForge.net 2007 community choice awards for “Technical Design” and for “Best Project”.