Express.js

// requiring and invoking express returns to us an 'app' function
var express = require('express');
var app = express();

// port can be an environment variable or just 3000
var port = process.env.PORT || 3000;

// use the static middleware to serve static files from public folder
app.use('/assets', express.static(__dirname + '/public'));

// reponse function to fire after a get request to '/'
app.get('/', function(req, res) {
  res.send('Hello World!')
});

// app.listen calls the standard Node http.createServer();
app.listen(port);