The RAM issue (if there was one) has nothing to do with the language in this case. If we are talking about lisp, then I assume we are referring to any true lisp

The RAM issue (if there was one) has nothing to do with the language in this case. If we are talking about lisp, then I assume we are referring to any true lisp, in which case the underlying hardware scenarios widely vary. I don't know how Arc does it but Clojure's resources are no different than any of the millions of Java web servers running; just a much better language to run on vs Java for that platform.