The CommonMark spec (spec.txt) and DTD (CommonMark.dtd) are

Copyright (C) 2014-16 John MacFarlane

Released under the Creative Commons CC-BY-SA 4.0 license:
<http://creativecommons.org/licenses/by-sa/4.0/>.

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The test software in test/ and the programs in tools/ are

Copyright (c) 2014, John MacFarlane

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The normalization code in runtests.py was derived from the
markdowntest project, Copyright 2013 Karl Dubost:

The MIT License (MIT)

Copyright (c) 2013 Karl Dubost

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