"All the pages can be rendered on both the client side via JavaScript as well as the server. How this work I cannot tell you"

There are plenty of templating engines that have been ported to Javascript. Mustache is the first example that comes to mind: http://mustache.github.com/

Once you have the templating engine the rest of the logic is pretty easy to build.

Rendering web apps entirely on the client in general is pretty awesome although there are two problems: 1) the push state API is not supported in all browsers yet, which forces you to resort the fragment identifier + onhashchange to approximate the same functionality. And of course the fragment identifier only affords you a fraction of the same luxuries as the push state API. And of course onhashchange is not supported in older browsers. 2) When you fall back to the fragment identifier rendering on the client is actually a little bit slower. The fragment identifier is not sent to the server meaning the javascript has to be loaded in the browser before anything at all is rendered. Does this lead to several seconds of delay? No. But it is noticeable. At least with push state you have the option of rendering the initial content on the server and all subsequent requests on the client without increasing complexity too much, assuming you have a good templating solution in place.

But yes I agree. Modern Web Apps are Here :)