Ask HN: In an alternate world, how would you re-create the web browser?

Here's a friendly thought exercise for everybody today: If HTML, CSS and JS ceased to exist, how would you re-create the web browser? Would it just be static documents again? Would you deliver bits of executable code to the browser and have it execute them?

If you want to make the thought exercise even more interesting, don't allow yourself the use of a VM. After all, just saying "we'll go back to Flash and Java" doesn't make for an interesting thought exercise. :)