Comment by zelphirkalt

The Beam VM handles memory copying, afaik. It is very much multi-process. It has very lightweight processes, of which you can spawn thousands. Those are then run in as many OS threads as makes sense and are available to the virtual machine. It is unclear what you mean by Erlang (the language) being single threaded. The VM easily runs on as many cores as you give it, probably by using as many or more OS threads.