This looks pretty cool!<p>I could never decide how to feel about the "How to Design ____" pedagogy.<p>On one hand, I envy people whose first exposure to programming was with Scheme, and there's a lovely sort of zen to the way the lessons build on each other that's refreshing.<p>But, having endured it myself at Northeastern, there's a sort of subtle arrogance and disrespect for the student that seeps out from time to time. If the authors and instructors could be more transparent on why things are taught the way they are as well as the broader context of the lessons, it would be much more effective.