Copyright notice and license for the libtess files (all source files besides
tessellate.[ch] and main.c):

SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.

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 including the dates of first publication and
either this permission notice or a reference to
http://oss.sgi.com/projects/FreeB/
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
SILICON GRAPHICS, INC. 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.

Except as contained in this notice, the name of Silicon Graphics, Inc.
shall not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization from
Silicon Graphics, Inc.

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Copyright notice for the other files:

SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
Copyright (C) 2013 AT&T Intellectual Property. All Rights Reserved.
