title: Javascript Frameworks with Rails
body: <p>Hoping someone can help clear things up for me.</p>
  
  <p>I've been reading a ton about the new javascript app frameworks out there, backbone.js, batman.js, ember.js etc...</p>
  
  <p>And I see a lot of instances of them using the frameworks on top of Rails.  </p>
  
  <p>Can someone explain to me.  Doesn't this require a ton of duplication in order to use them?  ie.  do I need to completely duplicate each model and controller?  And if so, do I need to make changes to both each time?</p>
  
  <p>I see a great benefit for rendering templates on the browser, but I feel like I'm missing something important when it comes to using these on top of an already well organized MVC structure.</p>
  
  <p>What is the benefit and is there really as much duplication as it seems?</p>
  
  <p>I've read the question  <a href="https://stackoverflow.com/questions/7990131/purpose-of-javascript-mvc-frameworks">here</a></p>
  
  <p>But it doesn't seem to address the duplication.</p>
  
  <p>Thanks in advance.</p>