Comment by KenSF

The move away from Scheme has always saddened me. The first thing we learned in 6.001 was abstraction and invariance. These are still the core of writing good software. I still use these principles every day. There is a purity to Scheme. It is a beautiful light-weight language anyone can learn over a weekend. It does nothing magical for you which means you get to / have to build everything you want and you must understand how it fits together.