JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//cdnjs.cloudflare.com/ajax/libs/handlebars.js/1.0.0-rc.3/handlebars.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/ember.js/1.0.0-rc.3/ember.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/showdown/0.3.1/showdown.min.js"></script>
<script type="text/x-handlebars">
	<div class="commentBox">
		<h1>Comments</h1>
		<div class="commentList"> 
			{{#each controller}}
				<div class="comment">
					<h2 class="commentAuthor">
						{{author}}
					</h2>
					<span>{{markdown text}}</span>
				</div>
			{{/each}}
		</div>
		{{input value=author placeholder="Your name"}}
		{{input value=text placeholder="Say something..."}}
		<input type="submit" value="Add" {{action addComment}} />
	</div>
</script>

JavaScript

App = Ember.Application.create();

App.ApplicationController = Ember.ArrayController.extend({
	model: [],
	content: [
		{ author: "Arthur", text: "This is awesome" },
		{ author: "Ember", text: "Another comment" }
	],

	addComment: function() {
		var comment = {
			author: this.get("author"),
			text:   this.get("text")
		};
		this.pushObject(comment);
		$.post("http://example.com", function(comments) {
			this.set("content", comments);
		});

		this.set("author", "")
		this.set("text", "")
	},

	init: function () {
		this._super();
		(function poll() {
			$.get("http://example.com", function (comments) {
				this.set("content", comments);
				setTimeout(poll, 5000);
			});
		})();
	}
});

Ember.Handlebars.registerBoundHelper('markdown', function(value, options) {
	var converter = new Showdown.converter();
	return new Handlebars.SafeString( converter.makeHtml(value || '') );
});