exemplo simples de socket com node
<html>
<head></head>
<body>
<div id="message"></div>
<script src="/socket.io/socket.io.js"></script>
<script>
var socket = io();
socket.on('message', function(msg){
console.log(msg);
document.getElementById("message").innerHTML = msg;
});
</script>
</body>
</html>