Reminds me a lot of Bret Victor's Inventing on Principle talk (http://vimeo.com/36579366). I went to the lecture he gave at Stanford back in February (http://hci.stanford.edu/courses/cs547/speaker.php?date=2013-...) and meant to ask him what ever happened to that editor he demonstrated. He's working on new software right now now that lets you take datasets (think plaintext CSV files) and programmatically construct new visual displays of those data (so perform this set of actions on each item, and repeat that through the entire set with this one change, which the software will learn to repeat through the rest of the data). That new software is web-based, but again, didn't hear anything from him about when to expect it to be released.
Very cool to see this stuff moving in the direction of being responsive inside the browser, and actually working. Understanding variables is one of the most common problems for beginners, and being able to change the variables and see the immediate effects in existing code is compelling.
Bret Victor has indeed been my primary inspiration for this project, even before the Inventing on Principle talk (e.g. Ladder of Abstraction, Kill Math, etc). I've written up some more details on the implementation and motivation here, if you're interested: http://www.jsdares.com/blindfold :-)
I agree very impressive. What it resonated with me is its kind of the web 2.0 equivalent of what we called a "programmers console". Classic blinking lights.
IF you follow that analogy, WRT the "Understanding variables" common problem as you state etc, a pretty obvious addition from the front panel area was ways to look at internal state. And breakpoints...
Very cool to see this stuff moving in the direction of being responsive inside the browser, and actually working. Understanding variables is one of the most common problems for beginners, and being able to change the variables and see the immediate effects in existing code is compelling.