You don't necessarily have to touch the markup directly, your app can essentially be pure JS (or compiled to pure JS) that paints it all into the DOM dynamicall

You don't necessarily have to touch the markup directly, your app can essentially be pure JS (or compiled to pure JS) that paints it all into the DOM dynamically (see http://cappuccino.org/ http://cappuccino.org/) You don't need a server-side language if the app doesn't really need to communicate with your server. You can do everything client-side with LocalStorage (SQLite) and cached assets. If the page has the right metadata on it, "Add to Home Screen" saves the whole app locally. And there's no reason why the server, if it needs to exist, shouldn't be executing the same language (see http://nodejs.org/ http://nodejs.org/) The modern web is the platform. There are nice local platforms, but your "write once run anywhere" 'native' app isn't going to fit in on any platform that actually gets used.