Free data compression software

PeaZip is a free and open-source file manager and file archiver for Microsoft Windows, Linux and BSD made by Giorgio Tani.

The Unarchiver is a free data decompression utility, which supports more formats than Archive Utility (formerly known as BOMArchiveHelper), the built-in archive unpacker program in OS X.

7-Zip is an open-source file archiver, an application used primarily to compress files.

Lempel–Ziv–Oberhumer (LZO) is a lossless data compression algorithm that is focused on decompression speed.

dar (disk archive) is a computer program, a command-line archiving tool intended as a replacement for tar in Unix-like operating systems.

UPX (Ultimate Packer for Executables) is a free and open source executable packer supporting a number of file formats from different operating systems.

xz is a lossless data compression program and file format which incorporates the LZMA/LZMA2 compression algorithms.

KGB Archiver is a file archiver and data compression utility based on the PAQ6 compression algorithm.

FreeArc is a free and open source file archiver developed by Bulat Ziganshin.

Archive Manager (previously File Roller) is the archive manager of the GNOME desktop environment.

lzip is a free, command-line tool for the compression of data; it employs the Lempel–Ziv–Markov chain algorithm (LZMA) with a user interface that is familiar to users of usual Unix compression tools, such as gzip and bzip2.

Zipeg is an open source free software that extracts files from compressed archives like ZIP, RAR, 7z and others, some of which are rarely used types.

zlib is a software library used for data compression.

bzip2 is a free and open-source file compression program that uses the Burrows–Wheeler algorithm.

gzip is a file format and a software application used for file compression and decompression.

Ark is a file archiver and compressor developed by KDE and included in the KDE Applications software bundle.

lzop is a free software file compression tool which implements the LZO algorithm and is licensed under the GPL.

AdvanceCOMP is a set of cross-platform command line data (re-)compression tools.

LZ4 is a lossless data compression algorithm that is focused on compression and decompression speed.

Info-ZIP is a set of open-source software to handle ZIP archives.

XZ Utils (previously LZMA Utils) is a set of free command-line lossless data compressors, including LZMA and xz, for Unix-like operating systems and, from version 5.

liblzg is a compression library for performing lossless data compression.

libzip is an open source library for handling zip archives.

The XAD system is an open source client based unarchiving system for the Amiga.

Xarchiver is a front-end to various command line archiving tools for Linux and BSD operating systems, designed to be independent of the desktop environment.

Zstandard (or Zstd) is a lossless data compression algorithm developed by Yann Collet at Facebook.

Snappy (previously known as Zippy) is a fast data compression and decompression library written in C++ by Google based on ideas from LZ77 and open-sourced in 2011.

pngcrush is a free and open source command-line utility for optimizing PNG image files.

ZPAQ is an open source (GPL) command line archiver for Windows and Linux.

The rzip program is huge-scale data compression software designed around initial LZ77-style string matching on a 900 MB dictionary window, followed by bzip2-based Burrows–Wheeler transform (BWT) and entropy coding (Huffman) on 900 kB output chunks.