[toast0]

As macintux, said they don't really compare. Messaging is everywhere in Erlang, in a way that nobody would do with a message queue. For example, you don't read or write to a tcp socket; you receive and send messages to a 'port'. The same is true for file i/o. Rather than calling a method on a shared object, you generally would send a message to a process that owns the state (or a process that manages the state in a database).

Sending messages to processes on other nodes has the same syntax as sending to a process on your node, which makes it easy to run a distributed system. (Ports are different, you'd have to setup a proxy process on the remote node in order to send/receive from that).

Of course, with the base of process to process messaging you can build a higher level messaging queue (see RabbitMQ for a popular message queue built in erlang).