v2.0.1: Very nice element, fast loading and really useful with coding website for example. I run up to the problem “Can’t find variable Polymer” when I copy the code to JSFIddle
Update 1: I got the element to start working, the problem is when you use Polymer object in javascript in index.html but do not safely wrap it then it may load without the imports ready. Two options, either to wrap it or declare another custom element and import it.