The menu which ties this site together was written by me in Lingo (Director) during my time at Vellis Knowledge Inc. Its used in Vellis courseware to manage a much larger body of knowledge than this site holds while keeping the production staff behind it sane. It looks good, the interface is easy to grasp yet deeply functional, and the menu builds on the fly when you load it, making maintenance easy.
Officially and legally, Vellis owns it, so Im afraid I can't give it away or tell you how it works, but I hope you like it.