Files under External/ folder are third party code under their own
respective licenses:

External/CSSLayout and/or External/Yoga:

    https://github.com/facebook/yoga
    Copyright (c) 2014-present, Facebook, Inc. All rights reserved
    BSD 3-Clause License

External/JsonParsers/MiniJson

    https://gist.github.com/darktable/1411710
    Copyright (c) 2013 Calvin Rien
    MIT license

External/JsonParsers/SimpleJson

    https://github.com/facebook-csharp-sdk/simple-json
    Copyright (c) 2011, The Outercurve Foundation
    MIT license

External/Mono.Cecil

    https://github.com/jbevain/cecil
    Copyright (c) 2008-2015 Jb Evain.  Copyright (c) 2008-2011 Novell, Inc.
    MIT license

External/Mono:

    https://github.com/boo-lang/boo
    Copyright (c) 2003-2008 Rodrigo B. Oliveira
    BSD 3-Clause License

    https://github.com/mono/mono/tree/master/mcs
    Copyright (c) 2005-2008 Novell, Inc.
    MIT License

    https://github.com/bamboo/unityscript
    Copyright (c) 2005-2008 Rodrigo B. Oliveira
    BSD 3-Clause License

External/NRefactory:
    https://github.com/icsharpcode/NRefactory
    Copyright (c) 2010-2014 AlphaSierraPapa, Xamarin
    MIT license

Appendix: Referenced Licenses

BSD 3-Clause License

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

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. 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.
    3. Neither the name of the copyright holder nor the names of its
       contributors may be used to endorse or promote products derived
       from this software without specific prior written permission.

    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.

MIT License

    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the
    "Software"), to deal in the Software without restriction, including
    without limitation the rights to use, copy, modify, merge, publish,
    distribute, sublicense, and/or sell copies of the Software, and to permit
    persons to whom the Software is furnished to do so, subject to the
    following conditions:

    The above copyright notice and this permission notice shall be included
    in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
    OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
    THE USE OR OTHER DEALINGS IN THE SOFTWARE.