Yes, you've hit the nail on the head. The same is true of some of Bret's demos like the Braid one. I was trying to bring some of that tangibility to difficult a

Yes, you've hit the nail on the head. The same is true of some of Bret's demos like the Braid one. I was trying to bring some of that tangibility to difficult abstract problems like from code jam. I think one of the reasons games developers are so ahead of the field in making the abstract visible is they have a "canvas" right there that they are outputting to. It's very common to see really clever and intuitive visualisations covering the screen in game development, not because those guys are visionaries but because they are just trying to understand the code and that's how they naturally express themselves. Basically what I wanted to do was come up with a solution "one step up the ladder of abstraction" (is my BV fanboy showing?) that let's users define their own, problem specific visualisations. This is where the concept of metacode came from. If you give people access to the data (omniscience), a blank canvas (sheet), and a way to express themselves (metacode) then natural curiosity should take over. I'm not saying I achieved all that, but that was the idea. I think there's more work to be done on the language of describing the code, the current vocabulary is based around line numbers and execution steps which are brittle when the code is changed. What you want is visualisations that persist and change as you edit the code.