ResearchWikis
ResearchWikis was (were?) the product of a company called ResearchBuy, whose business model seemed to be primarily selling premium content involving research into specific business sectors.
I created the site from scratch by taking a vanilla MediaWiki install, customizing the skin, and adding an extension to handle PayPal payments and mediating access to premium content.
ResearchBuy sent me .PSD files for how the pages should look, with no specifications about behavior; I extrapolated to the best of my ability and worked out a detailed bid and deliverables list, which they accepted. Apparently they were happy with the results, although the project was apparently not financially successful for them.
It always irked me that they seemed to think that the term "wiki" refers to an individual page rather than the whole site; the project should have been called "ResearchWiki" (singular). The domain "researchwiki.com" seems to have been available at the time.
Some of my original project notes are here.