What is the best way to Connecting Node.js code and openFrameworks(oF) code? I though zmq would be nice, because it seemed easy to use (has many wrappers), and light and fast. ofxZmq, the zmq addon for openFrameworks, however, just didn't work well. It crashes when receiving messages.

I want something as easy to use as possible.

I have done a simple communication from an open frameworks client to a node.js server via OSC protocol. It is very popular in the OF world, and it can be read by a bunch of similar software and frameworks (processing.org, PureData, VVVV, Max/MSP, etc)

Here you have some different chooses for OSC implementation via UDP:

https://nodejsmodules.org/tags/osc