We use 0MQ in our products at work. Once we got it set up correctly, it just worked! It makes distributed systems really easy to use. I can’t say enough about it.

We use ProtoBuf for the “formatting” of all the data the goes through 0MQ layer. They pair together nicely

This lets us pair together say a processor built in C on one machine to a test GUI built in Matlab on another machine without significant effort.