As far as learning is concerned, I think this is a wonderful idea. I say this in part because I myself learned on Logo before I taught people everything from Ja

As far as learning is concerned, I think this is a wonderful idea. I say this in part because I myself learned on Logo before I taught people everything from Java to Scheme, and even the simplest visualization tools could help immeasurably. For example, we had a tool called the Replacement Modeller that would visualize evaluation and substitution in pure-functional Scheme snippets, which was great for stepping through complex code and showing a student what was happening, and it was rocks-and-sticks next to the things Victor is proposing here. I'm interested, though, in what the ramifications are for advanced, complex programming. I am personally a Haskeller, and advanced Haskell regularly deals with incredibly abstract, difficult-to-visualize structures. Monads are infamous in this regard, and monads are embarrassingly trivial next to, say, comonads or iteratees. I have difficulty imagining this sort of model expanded beyond elementary visualization techniques, and certainly cannot imagine how one might represent and interact with these code structures. Victor seems to believe that visual, interactive systems such as these should become standard for all programmers, c.f. the section 'These Are Not Training Wheels.' The idea seems powerful, but: how?