Minimalistic starting point for Ember.js

HTML

<script src="https://github.com/downloads/emberjs/ember.js/ember-0.9.5.js"></script>
<script type="text/x-handlebars">
    {{view App.TFView}}
</script>

<script>
// Please change the info and fork this example
App = Em.Application.create({});
App.TFView = Em.TextField.extend({
    valueDidChange: function(){
        alert(42);        
    }.observes('value'),
});
</script>