XZ Utils

The XZ Utils (formerly LZMA Utils ) are a set of free data compression programs for Unix-like systems, the Linux distribution Slackware was created as part of the Tukaani Project.

The data compression algorithm is based on a custom port of the LZMA code of LZMA SDK written by Igor Pavlov on Linux and other Unix-like platforms.

The XZ Utils provide the established of the Linux Pack gzip and bzip2 programs usual compressed file handling for the progressive Lempel -Ziv - Markov data compression algorithm ( LZMA ) and a base for its easy integration into other programs. About porting the source code, it creates an established Linux Pack tools comparable total system for using LZMA. For this they have a very similar operation, also do the archiving multiple files yourself, but are committed to the combination with pure archive formats such as tar and also introduce a new file format with comparable properties ( xz, see below).

The source code is mostly public domain, otherwise under various free software licenses.

The compression is more efficient, but usually much slower than the compression with gzip, bzip2, or rare, however, for it leads to 30 % and 15 % smaller than gzip or bzip2 results. In LZMA -based compression result with sufficient memory of the compression settings largely independent, consistent decompression, which are usually well below the varying times of bzip2, but remain well in comparison with gzip.

The XZ Utils consist of several individual tools for handling xz files:

There is also a collection of shell scripts to facilitate the handling of xz files. This are the commands xz, unxz, xzcat and xzgrep (or for backwards compatibility with the older LZMA Utils also lzma, unlzma lzcat, and lzgrep ) are available.

Data format

The XZ Utils (as well as the LZMA Utils ) can not deal with the 7z format of the data LZMA reference implementation ( s) (7 -Zip, LZMA SDK). Create files in own xz format that works similarly to gz and bz2 format. Conversely, open xz files 7-Zip LZMA SDK and since the 9- versions as well.


The project began under the name of LZMA Utils as a Unix port of the LZMA code from the LZMA SDK, which produced only raw LZMA streams without any header data. The XZ Utils can emulate the behavior of the command line tools of LZMA Utils and open its files. The renaming was done with version 4.999.7beta on 31 December 2008. Since then, the file format ( xz ) is not changed. Since then, with xz also has a suitable container format, it is after the second lzip complete solution for using LZMA in Unix fashion, and have had this over now already more widespread.

As the LZMA SDK (of the XZ Utils are derived ) beta was public domain with version 4.61 of 23 November 2008 as a consequence, the license of the XZ Utils was changed accordingly.


The XZ Utils are available for various Linux distributions. As a binary package they are available, among others, as well. Deb package as well. Rpm package. Thus, the software can be easily installed in most Linux distributions. Packages, for example for Debian, Ubuntu, Gentoo, Mandriva, openSUSE, and Red Hat available.

Also for BSD operating systems are binary packages. Alternatively, users of BSD operating systems such as OpenBSD, NetBSD, FreeBSD, DragonFly BSD can install the software by the port system.

Since version 4.999.8beta there is also experimental support for Windows.