the most common compression formats are rar and zip.
among the free compression software at present, 7-zip is more powerful and supports the most compression formats.
7-Zip is an open source software. Most of the source code is distributed under the GNU LGPL license agreement. AES code is published under BSD license. UnRAR code is based on two kinds of licenses: GNU LGPL and unRAR restricted license. For more licensing information, please see: 7-Zip license.
You can use 7-Zip on any computer, including computers used for commercial purposes. Your use will not be affected if you don't donate or pay for 7-Zip.
main features of 7-zip
the 7z format using LZMA and LZMA2 algorithms has a very high compression ratio
supported formats:
compression/decompression: 7z, xz, bzip2, gzip, tar, zip and WIM
only
decompression: arj, cab, CHM, cpio. Dmg, fat, HFS, iso, lzh, lzma,
MBR, MSI, nsis, NTFS, rar, rpm, squashfs, UDF, vhd, WIM, xar, z
for ZIP and GZIP formats, 7-ZIP can provide a compression ratio of 2-1% higher than that using PKZip and WinZip
It provides a more perfect AES-256 encryption algorithm for 7z and Zip
7z format supports the creation of self-releasing compressed packages
Windows Explorer integration
Powerful file manager
A more powerful command-line version
Support for FAR Manager plug-ins
Support for 79.