That depends entirely on how you think about "turtles all the way down!" Primitives have to be built from something, our CPUs don't speak HTML natively. We'll

That depends entirely on how you think about "turtles all the way down!" Primitives have to be built from something, our CPUs don't speak HTML natively. We'll use jQuery as an example. People use jQuery bits to build widget sets for their own web UIs. Widget set libraries built on top of lower level libraries (primitives) that are themselves built on HTML/CS/JS. Companies like Microsoft are taking this to a whole new level with their Metro efforts. These kinds of things are where browsers fall down and go boom. As other people have said here, the world is trying to turn documents (unmarked up content) into applications. It was a good first crack at the idea of marking up documents with application code, but ultimately its warts are starting to show.