7-Zip is a compression software that claims to have the highest compression ratio today. It not only supports the unique 7z file format, but also supports various other compressed file formats, including ZIP, RAR, CAB, GZIP, BZIP2 and TAR. The compression ratio of this software is 30-50% higher than that of ordinary ZIP files. Therefore, it can further compress files compressed by WinZip by 2-10%.
