add zmq

[wangyenshu]

https://zeromq.org/

[anutosh491]

Not sure zmq would work but @DerThorsten might know better.

[IsabelParedes]

Correct, zmq would not work. It requires multi-threading and sockets which browsers do not support the same way as native platforms. You could replace this functionality using web workers and web sockets maybe, but that would require extensive changes. Depending on your use case, it might be easier to find alternatives that already work in a browser environment.