I looked around http://enable-cors.org/ but couldn't find any copyright/license information. Perhaps the site can be released under a Creative Commons license (cf. https://creativecommons.org)?
Michael, did the original site have an copyright info?
Not as far as I recall. CC BY sounds good?
If it's not CC-BY-SA just make it public domain or CC0. CC-BY is little more than an ego stroke.