well, it's funny because cmucl is a very sophisticated compiler. even a decade ago, back when things like Haskell or ocaml were considered to be "fringe" languages, beating cmucl was an achievement. with type annotations and knowing what you're doing, you can make it perform in the ballpark of C

The same applies to SBCL (a fork of CMUCL) which has more active development now. The funny thing is that the name of the compiler is Python. But this Python actually produces fast programs :) .