slime.el

(defun slime-compilation-finished (result)
   (with-struct (slime-compilation-result. notes duration successp) result
     (setf slime-last-compilation-result result)
     (slime-show-note-counts notes duration successp)
     (when slime-highlight-compiler-notes
       ;(slime-highlight-notes notes)
       (growl (format "%s" (second (first notes)))
     ;(run-hook-with-args 'slime-compilation-finished-hook notes)
       )))

I have this fn in my slime.el so when I M-c, the compiler notification is routed to growl instead of in an emacs buffer.