As you hinted at Common Lisp being an interpreted language, a clarification is in place.

Most Common Lisp implementations are compiled. As it has been for some time now. Some lisp implementation compile the code themselvel (SBCL for instance), others walk around and compile C-code (ecl for instance).

An overview of free CL implementations can be found at http://www.cliki.net/Common%20Lisp%20implementation .