How Wikipedia uses HTML5 to save bandwidth
jclaes.blogspot.com
jclaes.blogspot.com
Take a look at the template {{Should be SVG}} (http://en.wikipedia.org/wiki/Template:Should_be_SVG): it says "This image was uploaded in a raster graphics format such as PNG, GIF, or JPEG. However, it contains information that could be stored more efficiently and/or accurately in the SVG format, as a vector graphic."
Also, whenever you go to an article that displays an SVG image, it's actually a PNG rendering. It's only when you view the actual file that you see the SVG. Take a look at the United States article, for example. The image of the flag at the top is actually //upload.wikimedia.org/wikipedia/commons/thumb/e/e2/Flag_of_the_United_States_%28Pantone%29.svg/125px-Flag_of_the_United_States_%28Pantone%29.svg.png, not the SVG itself.
This may interest you, The HTML5 formatting[1] (Doctype and other magic) isn't enabled on en.wikipedia only MediaWiki wiki and the two test platforms:
'wgHtml5' => array(
'default' => false,
'mediawikiwiki' => true,
'testwiki' => true,
'test2wiki' => true,
),
[1]. http://www.mediawiki.org/wiki/Manual:$wgHtml5