I'm a developer at ArsDigita; I've been there for over two years. I work on the ArsDigitaCommunitySystem.
Check out http://www.martinfowler.com/isa/index.html (MartinFowler's Information Systems Architecture page).
My email address is mailto:richardl@arsdigita.com.
One thing I find marginally annoying with the Wiki is that it seems to rely on HTTP Referer headers for some features to work.