Comment by aidenn0

People like to say that "languages aren't fast or slow, that's a property of the implementation."

This is true, but the implementation is constrained by the specification. Python is not just dynamic, but in many cases over-specified. If you read e.g. the Common Lisp specification, you will find that things are under-specified in places that leave a lot of low-hanging fruit for an optimizing implementation.

Scheme (particularly prior to R6RS) is so lightly specified as to allow a lot of variation in implementation strategies, even more so than Common Lisp.