Example usage of runonce

test.js

var runOnce = require('uvrun').runOnce;

// Do something here, like make a server to keep the event loop busy
var TCP = process.binding('tcp_wrap').TCP;
var server = new TCP();
server.onconnection = function () {
  console.log("connection!");
};
server.bind("0.0.0.0", 3000);
server.listen(511);

// Visualize each event loop tick using a custom event loop.
console.log("Waiting for events...");
do {
  var ret = runOnce();
  console.log("tick", Date.now());
} while(ret);
// If the code gets here, there are no events left and node's built-in uv_run won't block.

Interesting way to achieve "parallel" execution. Is that any different from process.nextTick regarding performance?

It's not parallel, it's just a new event loop that blocks inside the built-in one.