WebKit has added native support for the 'srcset' attribute on <img> elements[1]. This means that future versions of Safari (and hopefully Chrome) will automatically load high-resolution thumbnails in MediaWiki pages when using a high-density display.

[1] https://www.webkit.org/blog/2910/improved-support-for-high-resolution-displa...

We added 'srcset' entries to MediaWiki image output last year, along with JavaScript fallback code to handle existing browsers. New browsers with native support will have three advantages over the previous behavior:

1) Works even with JavaScript off. 2) Avoids extra network transfers by only downloading the right size images for your screen. 3) Avoids brief 'flash' of low-resolution thumbnails before the JavaScript triggers.

I've confirmed on a current WebKit nightly on my Retina MacBook Pro that this works as expected -- our fallback code automatically disables itself and the native support handles things without a hitch!

After a few months this feature should trickle down to release versions of Chrome and Safari on mobile devices and laptops, so everybody will get slightly smoother page loads on their iDroids. :)

-- brion