7zip

7-Zip is a free and open-source file archiver for Windows, with ports to other platforms, created by Igor Pavlov. It provides a high-compression archive format and a suite of utilities for creating and extracting archives. The project was first released in 1999 and has since become one of the most popular compression tools, known for free distribution and robust performance.

At its core is the 7z archive format, which uses the LZMA and LZMA2 compression algorithms to achieve high ratios. 7-Zip supports multithreading, large dictionary sizes, and solid compression, which improves effectiveness for large collections. Archives can be encrypted with AES-256 and can be split into multiple volumes. The software can create and extract self-extracting archives on Windows.

Supported formats: The program can create archives in 7z, ZIP, GZIP, BZIP2 and TAR formats, and can unpack many other formats including ZIP, RAR (read-only), ISO, ARJ, CAB, CHM, DMG, CPIO, and more. It can also compress or extract with strong password protection.

Interface and usage: 7-Zip provides both a graphical user interface (7-Zip File Manager) and a command-line interface (7z, 7za, etc.). It integrates with Windows Explorer, allowing right-click context menu operations. On Linux and macOS, ports available via the p7zip project provide command-line tools.

Licensing and development: 7-Zip is free and open-source software released under the GNU Lesser General Public License. The source code is available on SourceForge and is maintained by a community of volunteers, with ongoing updates and improvements. It is widely used for data compression, backup, and distribution in personal and professional contexts.