7-Zip is a file archiver with a high compression ratio. 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, XZ, BZIP2, GZIP, TAR, ZIP and WIM
- Unpacking only: ARJ, CAB, CHM, CPIO, CramFS, DEB, DMG, FAT, HFS, ISO, LZH, LZMA, MBR, MSI, NSIS, NTFS, RAR, RPM, SquashFS, UDF, VHD, 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 79 languages