ZeroMQ usage in web application: how frontend interacts with backend

[streak]

I heard some facts about ZeroMQ, and I think it's very powerful thing. But now I try to imagine how it can be applied in web application.Could you make an example of using ZeroMQ in web applications?So, the first that strikes me - simple chat application. So, we need frontend and backend. I prefer using python+Tornado as backend. There is python lib for using ZeroMQ. It's clear. So, the next thing is frontend. In frontend I will use some javascript to interact with backend.So, to do this I should use ajax calls, right? Are there some other ways to do it?TIA!