I'm interested in learning what sort of problems are being solved "in the wild" with Lisp dialects–if Emacs Lisp and Clojure are removed from consideration—and why you choose a particular variant?

While Racket is an obviously popular dialect (and I'd love to hear what you're doing with it if that's your poison), I'm particularly interested in how Common Lisp, Scheme, or other Lisp dialects are being utilized these days.