I had just been reading an article at http://www.softwarefreedom.org/resources/2008/shareware.html when I came across Zorin O/S being sold on Ebay, nothing wrong with that until you look at the conditions. So as I see it the producers of Zorin O/S and probably many more are in violation of the requirement not to restrict access to software unless a fee is paid. Notice how Zorin require another donation if you want to update to the latest release..
From their website;
“How much does Zorin OS cost and how do I get it?
The Core, Lite and Educational versions are available to download for free from the Free download page. The Premium versions (Business, Gaming, Multimedia and Ultimate) are available in exchange for a donation on the Premium page for a physical DVD or a download. ”
“If I got an older version of one of the Zorin OS Premium releases would I get a free upgrade to the newer version?
You will have to either donate for a new physical DVD from the Premium page or a Download of it (see above) to upgrade to a newer version of your Premium release. “