Here you will find licensing information for each .js Javascript file that the CreRo instance you came from, and that is free software, loads.
This is the default setting of CreRo, and your exact server, which chose to use CreRo, may have added extra other .js dependecies from which this page cannot be aware.
To protect your privacy, to detect non-free and potentially dangerous embeded Javascript code on webpages you visit, you make want to take a look at the GNU Librejs project:
It's a browser extension that can be used to detect free Javascript, block non-free Javascript, and much more. CreRo, and the site you came from which uses CreRo, have complete support to
talk with Librejs about the freedom in their Javascript dependencies used !
Go to: gnu.org/software/librejs. Note that, currently, this is an extension for Mozilla-based web browsers, such as Firefox, Icecat, Tor-Browser... It will not work on Chromium-based browsers (Google Chrome, Chromium, etc), Safari, or Opera (AFAIK).

Format of each line is: (possibly minified) Javascript file link ; Free license of this Javascript File ; unminified, human-readable source code link for the Javascript file.