xz/COPYING

XZ Utils Licensing
==================

    Different licenses apply to different files in this package. Here
    is a rough summary of which licenses apply to which parts of this
    package (but check the individual files to be sure!):

      - liblzma is in the public domain.

      - xz, xzdec, and lzmadec command line tools are in the public
        domain unless GNU getopt_long had to be compiled and linked
        in from the lib directory. The getopt_long code is under
        GNU LGPLv2.1+.

      - The scripts to grep, diff, and view compressed files have been
        adapted from gzip. These scripts and their documentation are
        under GNU GPLv2+.

      - All the documentation in the doc directory and most of the
        XZ Utils specific documentation files in other directories
        are in the public domain.

        Note: The JavaScript files (under the MIT license) have
        been removed from the Doxygen-generated HTML version of the
        liblzma API documentation. Doxygen itself is under the GNU GPL
        but the remaining files generated by Doxygen are not affected
        by the licenses used in Doxygen because Doxygen licensing has
        the following exception:

            "Documents produced by doxygen are derivative works
            derived from the input used in their production;
            they are not affected by this license."

      - Translated messages are in the public domain.

      - The build system contains public domain files, and files that
        are under GNU GPLv2+ or GNU GPLv3+. None of these files end up
        in the binaries being built.

      - Test files and test code in the tests directory, and debugging
        utilities in the debug directory are in the public domain.

      - The extra directory may contain public domain files, and files
        that are under various free software licenses.

    You can do whatever you want with the files that have been put into
    the public domain. If you find public domain legally problematic,
    take the previous sentence as a license grant. If you still find
    the lack of copyright legally problematic, you have too many
    lawyers.

    As usual, this software is provided "as is", without any warranty.

    If you copy significant amounts of public domain code from XZ Utils
    into your project, acknowledging this somewhere in your software is
    polite (especially if it is proprietary, non-free software), but
    naturally it is not legally required. Here is an example of a good
    notice to put into "about box" or into documentation:

        This software includes code from XZ Utils <https://tukaani.org/xz/>.

    The following license texts are included in the following files:
      - COPYING.LGPLv2.1: GNU Lesser General Public License version 2.1
      - COPYING.GPLv2: GNU General Public License version 2
      - COPYING.GPLv3: GNU General Public License version 3

    Note that the toolchain (compiler, linker etc.) may add some code
    pieces that are copyrighted. Thus, it is possible that e.g. liblzma
    binary wouldn't actually be in the public domain in its entirety
    even though it contains no copyrighted code from the XZ Utils source
    package.

    If you have questions, don't hesitate to ask the author(s) for more
    information.