License

This software is made available under the 2-clause BSD license reproduced below. In addition, the authors grant patent rights, detailed below. These are separate and independent licenses.

Our policy on licensing is based on that of the WebM project. We deviated in using a 2-clause BSD license rather than a 3-clause BSD license. Nonetheless, the WebM FAQ may be helpful in understanding your rights.

Without prejudice to your rights granted below, if you wish to contribute to this distribution of Welly then we will require you to make the same grants.

Copyright license

Copyright 2007-2017, Thomas Lynn and Alistair Turnbull.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

  * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

  * Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
    distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Patent grant

Additional IP Rights Grant (Patents)
------------------------------------

"This implementation" means the copyrightable work that implements the Welly
language distributed by the Welly authors.

The Welly authors and contributors hereby grant to you a perpetual, worldwide,
non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this
section) patent license to make, have made, use, offer to sell, sell, import,
transfer, and otherwise run, modify and propagate the contents of this
implementation of Welly, where such license applies only to those patent
claims, both currently owned by the Welly authors and contributors and
acquired in the future, licensable by the Welly authors and contributors that
are necessarily infringed by this implementation of Welly. This grant does not
include claims that would be infringed only as a consequence of further
modification of this implementation. If you or your agent or exclusive
licensee institute or order or agree to the institution of patent litigation
or any other patent enforcement activity against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that any of this
implementation of Welly or any code incorporated within any of this
implementation of Welly constitute direct or contributory patent infringement,
or inducement of patent infringement, then any patent rights granted to you
under this License for this implementation of Welly shall terminate as of the
date such litigation is filed.