7-Zip is a ZIP compatible file archiver with highest compression ratio. The program is fully integrated to Windows Shell, so all archive operations like extracting, compressing and browsing can be executed using usual Windows Explorer. The program supports ZIP, RAR, CAB, GZIP, BZIP2 and TAR formats and for ZIP format it provides compression ratio that is 2-10 % better than ratio provided by any other zip compatible compression tools, like PKZip and WinZip. There is also additional powerful command line version of program for backup and other purposes. 7-Zip is freeware. In future sources and binaries of 7-Zip will be distributed under free software license. You can use 7-Zip without any fees and registering. However, if you like it and want to support further development of 7-Zip, please register it by paying a small fee.