Somewhat tangential (again thanks for the link, and the comments on "live programming"):

"In the Smalltalk model, for instance, state is persistent and code changes don't affect data. In the Clojure model, code is "mostly functional", with a small amount of carefully-managed state. Either model could be a starting point for a system where continuous code changes can be seen as continuous effects." -- Bret Victor http://worrydream.com/LearnableProgramming/