Nodejs in-memory storage

The server that node.js allows you to build, is an application server, which means that state is preserved, between request, on the server side. The following snippet demonstrates this:

var sys  = require('sys'),
    http = require('http');

var number = 0;

http.createServer(function (req, res) {
        console.log(req.method, req.url);

        res.writeHead(200, {'Content-Type': 'text/html'});
        res.write('<h1>Number is: ' + number + '</h1>');
        res.end();

        number++;

}).listen(8000);

sys.puts('Server running at http://127.0.0.1:8000/');

If you want more features have a look at redis-node-client

Or use a native node storage mechanism (written in node.js)

http://github.com/felixge/node-dirty