Yep. I think the right approach is to expose the browser's primitives and just have people write their own markup/layout/style languages if they want to. Keep HTML/CSS as a fall-back and because a lot of work has gone into optimizing their performance, but start the long-needed move to opening up mainstream browsers on a lower level. Also, of course, leave JS as a fall-back but introduce a lower-level language. Re-implement HTML/CSS/JS on top of the new exposed primitives in order to expedite moving to the new standards. So you'll be able to use either original, optimized HTML/CSS/JS, or the new HTML/CSS/JS that has been re-implemented on top of the new exposed primitives, or just new stuff built on those primitives.