Yeah, Lisp is a really good mind-bender. If you picked up some good experience with CLOS, I recommend using the Moose packages in your perl work. Moose adds t

Yeah, Lisp is a really good mind-bender. If you picked up some good experience with CLOS, I recommend using the Moose packages in your perl work. Moose adds to Lisp's default CLOS with lazy attributes, roles, and a functioning type system. SML, OCaml, and/or Haskell will show you a new way of looking at types (and secondarily, expose you to unification on a level that is a little deeper than destructuring-bind). If your background is in perl and then some Lisp experimentation, I recommend checking these others out in order to fill in this other nice piece in the equation. Finally, once you have convinced yourself that type systems are the hotness, it will be good to expose yourself to Erlang, specifically with regard to error handling and the role of supervisors for process restarts.