7-Zip

An alternative for WINZIP and WINRAR


7z is the new archive format, providing high compression ratio.
The main features of 7z format:

• Open architecture
• High compression ratio
• Strong AES-256 encryption
• Ability of using any compression, conversion or encryption method
• Supporting files with sizes up to 16000000000 GB
• Unicode file names
• Solid compressing
• Archive headers compressing

7z has open architecture, so it can support any new compression methods.

Download link:-
http://www.7-zip.org/download.html