index.js

var express = require('express'),
    app = express(),
    http = require('http').Server(app),
    WebSocketServer = require('ws').Server,
    wss = new WebSocketServer({
        port: 8080
    });

app.use(express.static('public'));

app.get('/', function(req, res) {
    res.sendFile(__dirname + '/index.html');
});

wss.broadcast = function broadcast(data) {
    wss.clients.forEach(function each(client) {
        client.send(data);
    });
};

wss.on('connection', function(ws) {
    ws.on('message', function(msg) {
        data = JSON.parse(msg);
        if (data.message) wss.broadcast('<strong>' + data.name + '</strong>: ' + data.message);
    });
});

http.listen(3000, function() {
    console.log('listening on *:3000');
});