I've used ZeroMQ lightly as a socket-replacement and for simple IPC and I'd say the key thing it solved was connection establishment. It turns out that opening

I've used ZeroMQ lightly as a socket-replacement and for simple IPC and I'd say the key thing it solved was connection establishment. It turns out that opening a two way connection between two apps on the same network without a clear starting order can go wrong in many ways and become quite messy to get right. With ZeroMQ it more or less just magically worked and it allowed me to focus on the actual problem I was working on. The wide range of language support was also nice. It allowed me to test the interface using a Python notebook which came in handy for debugging.