It's not clear to me what the policy is on links to copyright violating offers, e.g., "jQuery: Novice to Ninja: New Kicks and Tricks - SitePoint". SitePoint.com is currently asking $29 for that eBook, and graciously appears not to be applying DRM. Unfortunately, the phrase "really free" in CONTRIBUTING.md does not really resolve the question.

So what version of "free" does the list intend?