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.

HISTORY of the 7-Zip
--------------------

9.13 beta 2010-04-15
-------------------------
- 7-Zip now stores NTFS file timestamps to ZIP archives.
- New additional "Open archive >" item in context menu allows to select
archive type for some files.
- Some bugs were fixed.
- New localization: Uyghur.


http://www.7-zip.org/7zfm.png



You can use 7-Zip on any computer, including a computer in a commercial organization. You don't need to register or pay for 7-Zip.


The main features of 7-Zip

* High compression ratio in new 7z format with LZMA compression
* Supported formats:
o Packing / unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
o 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
* Strong AES-256 encryption in 7z and ZIP formats
* Self-extracting capability for 7z format
* Integration with Windows Shell
* Powerful File Manager
* Powerful command line version
* Plugin for FAR Manager
* Localizations for 74 languages


7-Zip works in Windows 7 / Vista / XP / 2008 / 2003 / 2000 / NT / ME / 98. There is a port of the command line version to Linux/Unix.

download

7-Zip for 32-bit Windows:

Code:
http://downloads.sourceforge.net/sevenzip/7z913.exe
7-Zip for 64-bit Windows x64:

Code:
 http://downloads.sourceforge.net/sevenzip/7z913-x64.msi