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