Koa – Next-generation web framework for Node.js
0s: "next generation web framework for node.js" (oh god, not another)5s: "designed by the team behind Express" (wait what?)6s: "Through leveraging generators Koa allows you to ditch callbacks" (wow, ok. oh hey, that makes "next generation" not just marketing fluff)18s:  app.use(function *(next){
    var start = new Date;
    yield next;
    var ms = new Date - start;
    this.set('X-Response-Time', ms + 'ms');
  });

(oh sweeet)