7-Zip is an open source file archiver with the high compression ratio predominantly for the Microsoft Windows operating system. It operates either as a command line program or with a graphical user interface. It also features integration with the Windows shell environment. 7-Zip is free software, developed by Igor Pavlov and distributed under the GNU LGPL license.

The main features of 7-Zip:
• 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