|Internet media type||
|Magic number||0xFD, '7', 'z', 'X', 'Z', 0x00|
|Developed by||The Tukaani Project|
|Latest release||1.0.4 / 27 August 2009|
|Developer(s)||The Tukaani Project|
|Stable release||5.0.5 / 30 June 2013|
|Preview release||5.1.3alpha / 26 October 2013|
xz can be thought of as a stripped down version of the 7-Zip program, although the latter was made with the former. xz has its own file format rather than the
.7z format used by 7-Zip which lacks support for Unix-like file system metadata.
xz compresses single files as input, and does not bundle multiple files into a single archive. It is therefore common to compress a file that is itself an archive, such as those created by the tar or cpio Unix programs.
Although the original 7-Zip program, which implements LZMA2 compression, is able to produce small files at the cost of speed, it also created its own unique archive format which was made primarily for Windows and did not support Unix functionality.
An implementation of the xz file format is freely available online as XZ Utils. It is licensed under the terms of the GNU LGPL and GNU GPL, with the bulk of the software (e.g., liblzma) in the public domain. Version 1.22 of GNU tar supports using this software to handle xz files transparently. FreeBSD tar has supported xz transparently since r191190 (released on April 17, 2009).
xz has gained notability for compressing packages in the GNU coreutils project, Debian family of systems deb (file format), Fedora, Arch Linux, Slackware, FreeBSD, Gentoo, GNOME, and TeX Live, as well as being an option to compress a compiled Linux kernel. In December 2013, the Linux kernel maintainers kernel.org announced that they would use xz instead of bzip2 as their compression tool from 2014 on.
- XZ Utils Release Notes (Git), Tukaaani
- Lindholm, Linux Gazette.
- XZ Utils Web site
- GNU tar Web site: References
- Changelog for Tar 1.22
- "release history", 7-Zip.
- "files" (FTP), Coreutils, GNU (see version 7.1 and newer files ending in .tar.xz).
- "XZ RPM payloads" (wiki), Features (12 ed.), Fedora.
- "Switching to xz compression for new packages", News, Archlinux.
- Entry (FTP) (changelog) (13.0 ed.), Slackware, Fri May 8 18:49:03 CDT 2009 .
- Stable (mailing list post), Free BSD, Jan 2011.
- "Remove .lzma in favor of .xz portage snapshots" (mailing list post), Dev (RFC), Gentoo.
- "Important: Switch of GNOME tarball compression format" (mailing list post), Devel, Gnome, Apr 2011.
- tex-archive/systems/texlive/tlnet/archive (directory), CTAN.
- xz embedded (Git), Tukaani.