I wouldn't say Pony (which is very interesting!) has the same concurrency style as Erlang. Yes, the both allow to send messages to other processes/actors in an

I wouldn't say Pony (which is very interesting!) has the same concurrency style as Erlang. Yes, the both allow to send messages to other processes/actors in an asynchronous (non-blocking) fashion. However Erlang supports also blocking operations (e.g. through a selective receive) beautifully and thereby allows to build blocking APIs on top of non-blocking messaging operations. Pony on the other hand is totally async. There is no way to block an actor for the result, e.g. in order to wait for a response. The only way to get some external input (response) is to give up the current branch of execution (return from the main behavior method) and wait for the next behavior to be executed. Pony is even more strict than other actor frameworks in this regard, because it even won't perform garbage collection inside an actor as long as it is actively running.