&gt; Absolutely anything goes. Examples: Racket (in the REPL), Lisp, Clojure, Scala, Erlang, etc.<p>Well you can&#x27;t mutate variables and data in Erlang. (Try X=1,X=2 in a repl, it will fail).  There is a thing called process dictionary but it is frowned upon. Concurency is handled by processes. But that&#x27;s a different thing.