archive then compress the directory ./keep/ into the file ./keep.txz tar xJf keep.txz # decompress then extract the file ./keep.txz creating the directory ./keep/ xz has supported multi-threaded compression (with the flag) since 2014, version 5.2.0.; since version 5.4.0 threaded decompression has been implemented. Threaded decompression requires multiple compressed blocks within a stream which are created by the threaded compression interface. The number of threads can be less than defined if the file is not big enough for threading with the given settings or if using more threads would exceed the memory usage limit. The xz format The xz format improves on lzma by allowing for preprocessing filters. The exact filters used are similar to those used in 7z, as 7z's filters are available in the public domain via the LZMA SDK. Development and adoption Development of XZ Utils took place within the Tukaani Project, which was led by Mike Kezner, by a small group of developers who once maintained a Linux distribution based on Slackware. All of the source code for xz and liblzma has been released into the public domain. The XZ Utils source distribution additionally includes some optional scripts and an example program that are subject to various versions of the GPL. Specifically, the full list of GPL scripts and sources distributed with the XZ Utils software include: An optional implementation of a common libc function, getopt (GNU GPL v2 and GNU LGPL v2.1) An m4 script for pthread detection (GNU GPL v3) Some nonessential wrapper scripts (xzgrep, etc) (GNU GPL v2) And the example program scanlzma, which is not integrated with the build system The resulting software xz and liblzma binaries are public domain, unless the optional LGPL getopt implementation is incorporated. Binaries are available for FreeBSD, NetBSD, Linux systems, Microsoft Windows, and FreeDOS. A number of Linux distributions, including Fedora, Slackware, Ubuntu, and Debian use xz for compressing their software packages. Arch Linux previously used xz to compress packages, but as of December 27, 2019, packages are compressed with Zstandard compression. The GNU FTP archive also uses xz. References External links Official Website SourceForge project page Free data compression software Free software programmed in C Public-domain software with source code Unix archivers and compression-related utilities