.. SPDX-FileCopyrightText: 2013-2021 Stefano Babic <stefano.babic@swupdate.org>
.. SPDX-License-Identifier: GPL-2.0-only

=======
License
=======

SWUpdate is Free Software.  It is copyrighted by Stefano Babic and
many others who contributed code (see the actual source code and the
git commit messages for details).  You can redistribute SWUpdate and/or
modify it under the terms of version 2 of the GNU General Public
License as published by the Free Software Foundation.  Some files can
also be distributed, at your option, under any later version of the
GNU General Public License -- see individual files for exceptions.

To make this easier, license headers in the source files will be
replaced with a single line reference to Unique License Identifiers
as defined by the Linux Foundation's SPDX project [1].  For example,
in a source file the full "GPL v2.0 only" header text will be
replaced by a single line:

::

	SPDX-License-Identifier:	GPL-2.0-only

Ideally, the license terms of all files in the source tree should be
defined by such License Identifiers; in no case a file can contain
more than one such License Identifier list.

If a "SPDX-License-Identifier:" line references more than one Unique
License Identifier, then this means that the respective file can be
used under the terms of either of these licenses, i. e. with

::

	SPDX-License-Identifier:	GPL-2.0-only OR BSD-3-Clause

you can choose between GPL-2.0-only and BSD-3-Clause licensing.

We use the SPDX_ Unique License Identifiers (SPDX-Identifiers_)

.. _SPDX: http://spdx.org/
.. _SPDX-Identifiers: http://spdx.org/licenses/

.. table:: Licenses

   +-------------------------------------------------+------------------+--------------+
   | Full name                                       |  SPDX Identifier | OSI Approved |
   +=================================================+==================+==============+
   | GNU General Public License v2.0_ only           | GPL-2.0-only     |    Y         |
   +-------------------------------------------------+------------------+--------------+
   | GNU Lesser General Public License v2.1_ or later| LGPL-2.1-or-later|    Y         |
   +-------------------------------------------------+------------------+--------------+
   | BSD 1-Clause_ License                           | BSD-1-Clause     |    Y         |
   +-------------------------------------------------+------------------+--------------+
   | BSD 2-Clause_ License                           | BSD-2-Clause     |    Y         |
   +-------------------------------------------------+------------------+--------------+
   | BSD 3-Clause_ "New" or "Revised" License        | BSD-3-Clause     |    Y         |
   +-------------------------------------------------+------------------+--------------+
   | MIT_ License                                    | MIT              |    Y         |
   +-------------------------------------------------+------------------+--------------+
   | Creative Commons Zero 1.0 Universal (CC0_)      | CC0-1.0          |    N         |
   +-------------------------------------------------+------------------+--------------+
   | Creative Commons Attribution Share Alike 4.0_   | CC-BY-SA-4.0     |    Y         |
   +-------------------------------------------------+------------------+--------------+
   | ISC License (ISC_)                              | ISC              |    Y         |
   +-------------------------------------------------+------------------+--------------+


.. _v2.0: http://www.gnu.org/licenses/gpl-2.0.txt
.. _v2.1: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt
.. _1-Clause: http://spdx.org/licenses/BSD-1-Clause
.. _2-Clause: http://spdx.org/licenses/BSD-2-Clause
.. _3-Clause: http://spdx.org/licenses/BSD-3-Clause
.. _MIT: https://spdx.org/licenses/MIT.html
.. _CC0: https://spdx.org/licenses/CC0-1.0.html
.. _4.0: https://spdx.org/licenses/CC-BY-SA-4.0.html
.. _ISC: https://spdx.org/licenses/ISC.html
