nodejs, create a simple http server
var http = require('http');
http.createServer(function(req, res){
res.wirteHead(200, {'Content-Type': 'text/html'});
res.wirte('<h1>Node.js</h1>');
res.end('<p>Hello World</p>');
}).listen(3000);
console.log("HTTP Server is lisetening at port 3000.");