Seconded!

Philipp Lenssen just posted a nice short piece on how Google's homepage would stack up in filesize when written in XHTML Strict compared to its current invalid HTML, Google Strict vs. Google Deprecated. I have to second what he says - any argument for keeping deprecated code based on filesize is quite silly. Valid XHTML (almost?) always reduces file size and both download and render times. Philipp's XHTML version comes in smaller than the current live Google version at 2.86k compared to 3.08k. Not a big difference, but multiple it a few million (billion?) times for all the traffic Google gets and it mounts up. Where I think you'd see a much bigger difference is on the actual search result pages. With much more data (all in tables, which beef up code size quite a lot), the difference should be much more marked. Aside from that, I imagine that the results pages are seen much more often than the homepage. With more and more browsers having search bars alongside their address bars, people will increasingly not use the actual front page of search engines as they go from a small input box in the browser itself to the results page. The results page would be harder to code in XHTML with CSS and still degrade properly in very old browsers (something Google has to think about more than most), but I'm sure it could be accomplished. Things are mad at work as we move a couple of hundred websites to a new server, but if I get the time and inspiration before someone else does, I might have a go at it as it's very interesting.