7-Zip

7-Zip is open source software. Most of the source code is under the GNU LGPL license

The main features of 7-Zip

• High compression ratio in 7z format with LZMA and LZMA2 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

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.

On 7-Zip's Source Forge Page you can find a forum, bug reports, and feature request systems.

Usually, 7-Zip compresses to 7z format 30-70% better than to zip format. And 7-Zip compresses to zip format 2-10% better than most of other zip compatible programs.

You can download it from HERE