E.4 Contributions

XTrackCAD incorporates the following software:

This program uses FreeImage, a free, open source image library supporting all common bitmap formats. 
See http://freeimage.sourceforge.net for details

uthash, utlist 
Copyright (c) 2005-2015, Troy D. Hanson  http://troydhanson.github.com/uthash/
All rights reserved.

CJson - https://github.com/DaveGamble/cJSON/blob/master/README.md#license
Copyright (c) 2009-2017 Dave Gamble and cJSON contributors

zlib - https://opensource.org/licenses/zlib-license.php

libzip - https://libzip.org/license/
Copyright (C) 1999-2019 Dieter Baron and Thomas Klausner

The authors can be contacted at <libzip@nih.at>

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. The names of the authors may not be used to endorse or promote
 products derived from this software without specific prior
 written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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.

minixml - https://github.com/michaelrsweet/mxml/commit/f166ad1977f2f13295689772a5d9e442f73d46f1

Copyright (C) 2003-2019 by Michael R Sweet.
The Mini-XML library is licensed under the Apache License Version 2.0 with an
exception to allow linking against GPL2/LGPL2-only software.