One has to stress: SBCL is probably by far the best Lisp compiler out there. So it is not only free, but also good. Might require a few type annotations to get

One has to stress: SBCL is probably by far the best Lisp compiler out there. So it is not only free, but also good. Might require a few type annotations to get the best performance though. And the diagnostic messages can sometimes be annoying, but they are right :)