“When the systems are truly complex, in short, programming has to be a process of exploration and discovery. That had been the whole point of interactive languages such as Lisp, as well as interactive-design tools such as Sketchpad: they made it easy to explore new solutions by making it easy to formulate and then reformulate ideas on the fly. And that was the whole point of Lick’s Dynamic Modeling project: he wanted to push exploratory programming as far as he could in every direction.”