Thank you for your inputs. As suggested, what I'm working on is a wiki based on mediawiki, one component of which will be an encyclopedic-type collection of sustainable development terminology, another which will be a case studies database. I think I will create a case_studies namespace for the case studies, since I like logical organizational separations of data and there doesn't seem to be a compelling reason not to do so.
It hadn't even occured to me that the term might be trademarked - thanks for the heads-up. So I will avoid using the term 'wikipedia' - perhaps a wiki-glossary? Doesn't have the same ring to it though I must say :).