fib.js

var http = require('http'),
    pool = require('threads_a_gogo').createPool(5).all.eval(fib);

function fib(n) {
    return (n < 2) ? 1 : (fib(n-2)+fib(n-1));
}

var server = http.createServer(function(req, res) {
    pool.any.eval('fib('+req.url.replace('/', '')+')', function(err, data) {
        res.writeHead(200);
        res.end(data+"\n");
    });
}).listen(8000);
console.log("server online at http://localhost:8000/");