If you think "enterprise" when someone says "distributed system," then you are not talking about the same kind of thing that jandrewrogers and I are talking about. We're talking about high performance computing (HPC), where the communication patterns among nodes in a cluster can be complex and dominate performance. I disagree with his strong statement that if something like ZMQ works for you, it's not a distributed system, but otherwise, everything he has said is spot on.