In reply to Karen Jeannette.

I added the non-commercial and share-alike clauses over time as companies used my work to generate revenue, and in some cases not attributing my work. I agree that commercial use can be a fuzzy area. I would say that if a university copies my material for a course that requires a fee, then it is a commercial purpose. If they link to my material/site, then it is not commercial. Of course, American law covers "fair use" quite broadly, so you may be covered by that. In Canada, "fair dealing" is less comprehensive.