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.

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.

Features:

  • High compression ratio in new 7z format with LZMA compression
  • Supported formats:
    • Packing / unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
    • Unpacking only: RAR, CAB, ISO, ARJ, LZH, CHM, MSI, WIM, Z, CPIO, RPM, DEB and NSIS
  • 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 69 languages

What's New:

  • The default number of LZMA2 chunks per solid block in 7z archive was increased to 64. It allows to increase the compression speed for big 7z archives, if there is a big number of CPU cores and threads.
  • The speed of PPMd compressing/decompressing was increased for 7z/ZIP/RAR archives.
  • The new -ssp switch. If the switch -ssp is specified, 7-Zip doesn't allow the system to modify "Last Access Time" property of source files for archiving and hashing operations.
  • Some bugs were fixed.
  • New localization: Swahili.