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.

Feature:

• High compression ratio in new 7z format with LZMA compression
• Supported formats:
  • 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
• 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

System Requirements:

• Operating System: Windows All Version
• Language: English-US
• License: Open Source
• Author: 7-zip
• Website: www.7-zip.org

Changelog:

• 7-Zip now can unpack UEFI BIOS files.
• 64-bit version of 7-Zip now includes additional 32-bit shell extension DLL. So other 32-bit programs can call 64-bit 7-Zip via context menu.
• Now it’s possible to associate 7-Zip with file types without Administrator rights.
  New -mf=FilterID switch to specify compression filter. Examples:
  7z a -mf=bcj2 a.7z a.tar
  7z a -mf=delta:4 a.7z a.wav
  7z a -mf=bcj a.tar.xz a.tar
• 32-bit 7-Zip running under 64-bit Windows now can use up to 4 GB of RAM.
• Some bugs were fixed.
• New localizations: Corsican, Kyrgyz, Ligurian.

7-Zip 9.21 Beta (32-bit)