title: How do you render hashes as JSON in Rails 3
body: <p>I found how to render ActiveRecord objects in Rails 3, however I cannot figure out how to render any custom objects.  I am writing an app without ActiveRecord.  I tried doing something like this:</p>
  
  <pre><code>class AppController &lt; ApplicationController
    respond_to :json
  
    ...
    def start
      app.start
      format.json { render :json =&gt; {'ok'=&gt;true} }
    end
  end
  </code></pre>