Akka-zeromq-java is a project mainly written in Java, it's free.
Examples of using Akka and 0MQ in Java, separately and together.
This is code from my CIJUG talk on Actors. I presented things in this order: 1) akka/AsyncSend 2) akka/AsyncRequestReply 3) akka/Pi <=== this is the one that pegged my 8-core machine to 100% CPU for about 14 secs 4) akka/weather 5) zeromq/Server & Client 6) zeromq/Publisher & Subscriber 7) akkazeromq
The pom defines the Akka dependencies, but 0MQ isn't in any maven repos I can find, so zmq.jar is included in the lib directory just to get everything to compile.
To actually run the 0MQ examples you'll need both the 0MQ C library as well as the 0MQ JNI library.