[yoursunny]

IFRAMEs still require a top-level page and their positions still need CSS.

I usually use FRAMESET and FRAMEs: they are positioned perfectly in a grid, with no need for CSS or TABLE. There's no postMessage API: you can write <A target=other-frame-name> to navigate to a page in another FRAME.

HTML5 doesn't have FRAMESET, but all the browsers still support HTML4 perfectly.