I’ve been recently experimenting with Polymer to get a feel for what it was all about. While it’s still experimental and only available currently in some of the browsers, it’s also among the more innovative technologies to come to the web in recent memory. Let’s start with how Google describes it: Web Components usher in a new era of web development based on encapsulated and interoperable custom elements that extend HTML itself. Built atop these new standards, Polymer makes it easier and faster to create anything from a button to a complete application across desktop, mobile, and beyond. There are four specifications that form web components. All are under consideration in the new Microsoft Edge browser too (you can see this currently at http://dev.modern.ie/platform/status/ and even vote that you want engineering to prioritize it higher): Custom Elements: enabling the author to define and use new types of DOM elements in a document. Shadow DOM: combining multiple DOM trees into one hierarchy and how these trees interact with each other within a document, thus enabling better composition of the DOM. HTML Imports: include and reuse HTML documents in other HTML documents. HTML Templates: declare fragments of HTML that can be cloned and inserted in the document by script.