Edit in JSFiddle

var View = ripple('#template')
  .use(ripple.events)
  .use(ripple.markdown);

View.prototype.change = function(event) {
  this.set('text', event.target.value);  
};

var view = new View({
  data: { 
    text: '# title' 
  }   
});

view.appendTo(document.body);

<script type="text/template" id="template">
  <div id="editor">
    <textarea on-input="{{ this.change }}">{{text}}</textarea>
    <div markdown="{{text}}"></div>   
  </div>
</script>