Miniz is a lossless data compression library that implements the zlib (RFC 1950) and Deflate (RFC 1951) compressed data format specification standards. It supports the most commonly used functions exported by the zlib library.

bzip2 is a freely available, patent free (see below), high-quality data compressor. It typically compresses files to within 10% to 15% of the best available techniques (the PPM family of statistical compressors), whilst being around twice as fast at compression and six times faster at decompression.

The Ultimate Packer for eXecutables (UPX) is an executable file compressor. UPX typically reduces the file size of programs and shared libraries by around 50%--70%, thus reducing disk space, network load times, download times, and other distribution and storage costs.

Snappy is a compression/decompression library. It does not aim for maximum compression, or compatibility with any other compression library; instead, it aims for very high speeds and reasonable compression. For instance, compared to the fastest mode of zlib, Snappy is an order of magnitude faster for most inputs, but the resulting compressed files are anywhere from 20% to 100% bigger.

This package provides the reference implementation of Brotli, a generic-purpose lossless compression algorithm that compresses data using a combination of a modern variant of the LZ77 algorithm, Huffman coding and 2nd order context modeling, with a compression ratio comparable to the best currently available general-purpose compression methods. It is similar in speed with deflate but offers more dense compression.

The specification of the Brotli Compressed Data Format is defined in RFC 7932.

The purpose of libmspack is to provide both compression and decompression of some loosely related file formats used by Microsoft.

ZPAQ is a command-line archiver for realistic situations with many duplicate and already compressed files. It backs up only those files modified since the last update. All previous versions remain untouched and can be independently recovered. Identical files are only stored once (known as de-duplication). Archives can also be encrypted.

ZPAQ is intended to back up user data, not entire operating systems. It ignores owner and group IDs, ACLs, extended attributes, or special file types like devices, sockets, or named pipes. It does not follow or restore symbolic links or junctions, and always follows hard links.

Squashfs is a highly compressed read-only file system for Linux. It compresses files, inodes, and directories with one of several compressors. All blocks are packed to minimize the data overhead, and block sizes of between 4K and 1M are supported. It is intended to be used for archival use, for live media, and for embedded systems where low overhead is needed.

The squashfs-tools-ng package offers alternative tooling to create and extract such file systems. It is not based on the older squashfs-tools package and its tools have different names:

1. gensquashfs produces SquashFS images from a directory or gen_init_cpio-like file listings and can generate SELinux labels.

2. rdsquashfs inspects and unpacks SquashFS images.

3. sqfs2tar and tar2sqfs convert between SquashFS and tarballs.

4. sqfsdiff compares the contents of two SquashFS images.

These commands are largely command-line wrappers around the included libsquashfs library that intends to make SquashFS available to other applications as an embeddable, extensible archive format.

Both the library and tools operate deterministically: same input will produce byte-for-byte identical output.

Lziprecover is a data recovery tool and decompressor for files in the lzip compressed data format (.lz). It can test the integrity of lzip files, extract data from damaged ones, and repair most files with small errors (up to one single-byte error per member) entirely.

Lziprecover is not a replacement for regular backups, but a last line of defence when even the backups are corrupt. It can recover files by merging the good parts of two or more damaged copies, such as can be easily produced by running ddrescue on a failing device.

This package also includes unzcrash, a tool to test the robustness of decompressors when faced with corrupted input.

unrar-free is a free software version of the non-free unrar utility. This program is a simple command-line front-end to libarchive, and can list and extract not only RAR archives but also other formats supported by libarchive. It does not rival the non-free unrar in terms of features, but special care has been taken to ensure it meets most user's needs.

zlib is designed to be a free, general-purpose, legally unencumbered -- that is, not covered by any patents -- lossless data-compression library for use on virtually any computer hardware and operating system. The zlib data format is itself portable across platforms. Unlike the LZW compression method used in Unix compress(1) and in the GIF image format, the compression method currently used in zlib essentially never expands the data. (LZW can double or triple the file size in extreme cases.) zlib's memory footprint is also independent of the input data and can be reduced, if necessary, at some cost in compression.

Ziptime helps make .zip archives reproducible by replacing timestamps in the file header with a fixed time (1 January 2008).

``Extra fields'' are not changed, so you'll need to use the -X option to zip to prevent it from storing the ``universal time'' field.

Lzip is a lossless data compressor with a user interface similar to the one of gzip or bzip2. Lzip decompresses almost as fast as gzip and compresses more than bzip2, which makes it well-suited for software distribution and data archiving. Lzip is a clean implementation of the LZMA algorithm.

This package provides a script to unpack self-extracting archives generated by makeself or mojo without running the possibly untrusted extraction shell script.

A data compression/decompression library for embedded/real-time systems.

Among its features are:

• Low memory usage (as low as 50 bytes.) It is useful for some cases with less than 50 bytes, and useful for many general cases with less than 300 bytes.

• Incremental, bounded CPU use. It can be used to chew on input data in arbitrarily tiny bites. This is a useful property in hard real-time environments.

• Can use either static or dynamic memory allocation.

The main command is aunpack which extracts files from an archive. The other commands provided are apack (to create archives), als (to list files in archives), and acat (to extract files to standard out). As atool invokes external programs to handle the archives, not all commands may be supported for a certain type of archives.

Parallel Zstandard (PZstandard or pzstd) is a multi-threaded implementation of the Zstandard compression algorithm. It is fully compatible with the original Zstandard file format and command-line interface, and can be used as a drop-in replacement.

Compression is distributed over multiple processor cores to improve performance, as is the decompression of data compressed in this manner. Data compressed by other implementations will only be decompressed by two threads: one performing the actual decompression, the other input and output.

The existing XZ Utils provide great compression in the .xz file format, but they produce just one big block of compressed data. Pixz instead produces a collection of smaller blocks which makes random access to the original data possible and can compress in parallel. This is especially useful for large tarballs.

FastJar is an attempt to create a much faster replacement for Sun's jar utility. Instead of being written in Java, FastJar is written in C.

Lhasa is a replacement for the Unix LHa tool, for decompressing .lzh (LHA / LHarc) and .lzs (LArc) archives. The backend for the tool is a library, so that it can be reused for other purposes. Lhasa aims to be compatible with as many types of .lzh/lzs archives as possible. It also aims to generate the same output as the (non-free) Unix lha tool, so that it will act as a free drop-in replacement.

Archive huge numbers of files, or split massive tar archives into smaller chunks.

minizip-ng is a zip manipulation library written in C, forked from the zip manipulation library found in the zlib distribution.

ECM is a utility that converts ECM files, i.e., CD data files with their error correction data losslessly rearranged for better compression, to their original, binary CD format.

Xarchiver is a front-end to various command line archiving tools. It uses GTK+ tool-kit and is designed to be desktop-environment independent. Supported formats are 7z, ARJ, bzip2, gzip, LHA, lzma, lzop, RAR, RPM, DEB, tar, and ZIP. It cannot perform functions for archives, whose archiver is not installed.