There are lessons there for improving live editing environments (whether Khan Academy's, or p5.js', or ...), but also a call to rethink teaching (programming) in general.

Processing is clearly on the right track given all the wonderful things that have already been made with it ... consider how many more people it could reach, how much more wonder could exist, if Processing were to move beyond `ellipse(50, 50, 80, 80)` (for example).