In fact Elixir and Erlang are the only reasonably known dynamic languages that differentiate on concurrency. The rest either do higher order event loop concurrency, which is ok, but not a differentiator, or do worse, shared memory multithreading (threads, coroutines with synchronous channels, mutexes, etc.)
I don't really know what "differentiate" means, but Clojure has support for CSP-channel style with core.async, shared-memory with transactions using atoms/refs, and actor-ish style with the agents.
