1 2XZ Utils Licensing 3================== 4 5 Different licenses apply to different files in this package. Here 6 is a rough summary of which licenses apply to which parts of this 7 package (but check the individual files to be sure!): 8 9 - liblzma is under the BSD Zero Clause License (0BSD). 10 11 - The command line tools xz, xzdec, lzmadec, and lzmainfo are 12 under 0BSD except that, on systems that don't have a usable 13 getopt_long, GNU getopt_long is compiled and linked in from the 14 'lib' directory. The getopt_long code is under GNU LGPLv2.1+. 15 16 - The scripts to grep, diff, and view compressed files have been 17 adapted from GNU gzip. These scripts (xzgrep, xzdiff, xzless, 18 and xzmore) are under GNU GPLv2+. The man pages of the scripts 19 are under 0BSD; they aren't based on the man pages of GNU gzip. 20 21 - Most of the XZ Utils specific documentation that is in 22 plain text files (like README, INSTALL, PACKAGERS, NEWS, 23 and ChangeLog) are under 0BSD unless stated otherwise in 24 the file itself. The files xz-file-format.txt and 25 lzma-file-format.xt are in the public domain but may 26 be distributed under the terms of 0BSD too. 27 28 - Doxygen-generated HTML version of the liblzma API documentation: 29 While Doxygen is under the GNU GPLv2, the license information 30 in Doxygen includes the following exception: 31 32 Documents produced by doxygen are derivative works 33 derived from the input used in their production; 34 they are not affected by this license. 35 36 Note: The JavaScript files (under the MIT license) have 37 been removed from the Doxygen output. 38 39 - The XZ logo (xz-logo.png) included in the Doxygen-generated 40 documentation is under the Creative Commons BY-SA 4.0 license. 41 42 - Translated messages and man pages are under 0BSD except that 43 some old translations are in the public domain. 44 45 - Test files and test code in the 'tests' directory, and 46 debugging utilities in the 'debug' directory are under 47 the BSD Zero Clause License (0BSD). 48 49 - The GNU Autotools based build system contains files that are 50 under GNU GPLv2+, GNU GPLv3+, and a few permissive licenses. 51 These files don't affect the licensing of the binaries being 52 built. 53 54 - The extra directory contain files that are under various 55 free software licenses. 56 57 For the files under the BSD Zero Clause License (0BSD), if 58 a copyright notice is needed, the following is sufficient: 59 60 Copyright (C) The XZ Utils authors and contributors 61 62 If you copy significant amounts of 0BSD-licensed code from XZ Utils 63 into your project, acknowledging this somewhere in your software is 64 polite (especially if it is proprietary, non-free software), but 65 it is not legally required by the license terms. Here is an example 66 of a good notice to put into "about box" or into documentation: 67 68 This software includes code from XZ Utils 69 <https://xz.tukaani.org/xz-utils/>. 70 71 The following license texts are included in the following files: 72 - COPYING.0BSD: BSD Zero Clause License 73 - COPYING.LGPLv2.1: GNU Lesser General Public License version 2.1 74 - COPYING.GPLv2: GNU General Public License version 2 75 - COPYING.GPLv3: GNU General Public License version 3 76 - COPYING.CC-BY-SA-4.0: Creative Commons Attribution-ShareAlike 4.0 77 International Public License 78 79 A note about old XZ Utils releases: 80 81 XZ Utils releases 5.4.6 and older and 5.5.1alpha have a 82 significant amount of code put into the public domain and 83 that obviously remains so. The switch from public domain to 84 0BSD for newer releases was made in Febrary 2024 because 85 public domain has (real or perceived) legal ambiguities in 86 some jurisdictions. 87 88 There is very little *practical* difference between public 89 domain and 0BSD. The main difference likely is that one 90 shouldn't claim that 0BSD-licensed code is in the public 91 domain; 0BSD-licensed code is copyrighted but available under 92 an extremely permissive license. Neither 0BSD nor public domain 93 require retaining or reproducing author, copyright holder, or 94 license notices when distributing the software. (Compare to, 95 for example, BSD 2-Clause "Simplified" License which does have 96 such requirements.) 97 98 If you have questions, don't hesitate to ask for more information. 99 The contact information is in the README file. 100 101
