Google Code: Web Authoring Statistics
Google recently analyzed the use of HTML code throughout the Web using (as only they can) a sample of over a billion documents. The report is certainly worth a read and very entertaining at times:
There really is no reason for using language these days. It’s been deprecated since forever, and quite obviously a lot of people can’t spell it. And given that more than half of pages specify the type attribute anyway… this is probably mostly a matter of “just in case” cargo-cult authoring.
Looking past the thought-provoking research materials, the SVG graphs are also a handy test for your SVG-compatible browsers (e.g., Firefox 1.5+).

