Blosc is a high performance compressor optimized for binary data. It has been designed to transmit data to the processor cache faster than the traditional, non-compressed, direct memory fetch approach via a memcpy() system call. Blosc is meant not only to reduce the size of large datasets on-disk or in-memory, but also to accelerate memory-bound computations.

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.

Zstandard (zstd) is a lossless compression algorithm that combines very fast operation with a compression ratio comparable to that of zlib. In most scenarios, both compression and decompression can be performed in ‘real time’. The compressor can be configured to provide the most suitable trade-off between compression ratio and speed, without affecting decompression speed.

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.

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.

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.

lbzip2 is a multi-threaded compression utility with support for the bzip2 compressed file format. lbzip2 can process standard bz2 files in parallel. It uses POSIX threading model (pthreads), which allows it to take full advantage of symmetric multiprocessing (SMP) systems. It has been proven to scale linearly, even to over one hundred processor cores. lbzip2 is fully compatible with bzip2 – both at file format and command line level.

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.

Lzop is a file compressor which is very similar to gzip. Lzop uses the LZO data compression library for compression services, and its main advantages over gzip are much higher compression and decompression speed (at the cost of some compression ratio).

Blosc is a high performance compressor optimized for binary data (i.e. floating point numbers, integers and booleans, although it can handle string data too). It has been designed to transmit data to the processor cache faster than the traditional, non-compressed, direct memory fetch approach via a memcpy() system call. Blosc main goal is not just to reduce the size of large datasets on-disk or in-memory, but also to accelerate memory-bound computations.

C-Blosc2 is the new major version of C-Blosc, and is backward compatible with both the C-Blosc1 API and its in-memory format. However, the reverse thing is generally not true for the format; buffers generated with C-Blosc2 are not format-compatible with C-Blosc1 (i.e. forward compatibility is not supported).

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.

Lunzip is a decompressor for files in the lzip compression format (.lz), written as a single small C tool with no dependencies. This makes it well-suited to embedded and other systems without a C++ compiler, or for use in applications such as software installers that need only to decompress files, not compress them. Lunzip is intended to be fully compatible with the regular lzip package.

lrzip is a compression utility that uses long-range redundancy reduction to improve the subsequent compression ratio of larger files. It can then further compress the result with the ZPAQ or LZMA algorithms for maximum compression, or LZO for maximum speed. This choice between size or speed allows for either better compression than even LZMA can provide, or a higher speed than gzip while compressing as well as bzip2.

QuaZIP is a simple C++ wrapper over Gilles Vollant's ZIP/UNZIP package that can be used to access ZIP archives. It uses Trolltech's Qt toolkit.

QuaZIP allows you to access files inside ZIP archives using QIODevice API, and that means that you can also use QTextStream, QDataStream or whatever you would like to use on your zipped files.

QuaZIP provides complete abstraction of the ZIP/UNZIP API, for both reading from and writing to ZIP archives.

SfArkLib is a C++ library for decompressing SoundFont files compressed with the sfArk algorithm.

Libzip is a C library for reading, creating, and modifying zip archives. Files can be added from data buffers, files, or compressed data copied directly from other zip archives. Changes made without closing the archive can be reverted.

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.

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.

Minizip is a minimalistic library that supports compressing, extracting and viewing ZIP archives. This version is extracted from the zlib source.

GNU Gzip provides data compression and decompression utilities; the typical extension is ".gz". Unlike the "zip" format, it compresses a single file; as a result, it is often used in conjunction with "tar", resulting in ".tar.gz" or ".tgz", etc.

innoextract allows extracting Inno Setup installers under non-Windows systems without running the actual installer using wine.

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.

Zutils is a collection of utilities able to process any combination of compressed and uncompressed files transparently. If any given file, including standard input, is compressed, its decompressed content is used instead.

zcat, zcmp, zdiff, and zgrep are improved replacements for the shell scripts provided by GNU gzip. ztest tests the integrity of supported compressed files. zupdate recompresses files with lzip, similar to gzip's znew.

Supported compression formats are bzip2, gzip, lzip, and xz. Zutils uses external compressors: the compressor to be used for each format is configurable at run time, and must be installed separately.

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.