Koa is the successor of Express, written by Express creator, TJ. I like it because generator workflow makes writing apps better since we can yield promises. Code is much cleaner.<p><pre><code>  app.get(&#x27;&#x2F;&#x27;, function * () {
    this.body = yield User.all()
  })
</code></pre>
vs<p><pre><code>  app.get(&#x27;&#x2F;&#x27;, function (req, res) {
    User.all(function (err, users) {
      if (err) throw err
      res.end(users)
    })
  })</code></pre>