TurboGears is a framework to quickly build a web application using Python. Main features: You define the model, TG creates everything else which can then adjust to your needs. Changes in the model need a restart of the development server, everything else happens at the next reload in the web browser (TG will let you knew when you need to restart).
A big step forward, especially the 2.0 release (which should come out "real soon, now" - no offense, guys, I know you're hard working on this for several years ... but no TG 2.0 for me for several years, either :( ) Web only, though. So we'd have to implement all the drag'n'drop ourselves, find a way to paint a navigable graph. Frustratingly close.