I haven't been a bit user of any of these. I've been using the MQP one a while ago. So I don't really know where it's at these days. Message queues are interesting, they're a way to add crazy scalability. If you've got a lot of stuff that takes a while, but you don't need the answer right away,. They're pretty interesting, but I just haven't needed them much myself either. Not too long ago, speak with Min Regan Kelly about zero MQ and Python. And apparently they're doing a lot of cool stuff for powering Jupiter with zero MQ.