Clever beats just fast? I think the idea behind PyPy is that the high-level language is more flexible, and allows trying many different approaches, rather than

Clever beats just fast? I think the idea behind PyPy is that the high-level language is more flexible, and allows trying many different approaches, rather than heavily optimizing one or two possibly sub-optimal approaches in a low-level language. Also, if you write the core in the language itself, when you improve your optimizations, you speed the core up too.