SBCL probably does more type checking that one thinks. It catches many useful type errors and warnings, especially since we get them instantly, after we compile

SBCL probably does more type checking that one thinks. It catches many useful type errors and warnings, especially since we get them instantly, after we compile a function with a keyboard shortcut. Then we have the new Coalton library, that brings ML-like type checking on top of CL. (and yes CL still has killer features, and no one brings all of them together!)