Hello,
I just came across zeromq a low footprint, yet interesting open source, messaging infrastructure. It seems very interesting for various peer to peer messaging needs.
I wonder if i should make the effort and try to connect it somehow to swi prolog
Dan
More interfaces is always better 
If there is no need to connect to an infrastructure that uses this, there is already support for Redis and STOMP. The latter allows talking to several message brokering system, among which RabbitMQ. All open source
The amount of work to connect to yet another depends on the complexity. STOMP was easy, but it can’t do much. Redis is both a data store and message brokering system. It has quite a few sophisticated data structures that make the interface non-trivial as well as quite powerful.
If ZeroMQ talks STOMP you can already talk to it