"The phase that saw dynamic programming development tools be sold for significant sums of money altered the Lisp implementation landscape significantly, and today we have commercial implementations like Lispworks and Allegro, which while excellent, are expensive. This pulls enough talent away from open source implementations, of which there are several, that they all remain somewhat warty."

This assumes lisp = Common Lisp.

Clojure for example is entirely Open Source and a delight to code in.