[giantrobot]

WebKit and Gecko based browsers, so basically every device with a screen, supports XSLT 1.0 just fine. Even the old IE Trident engine had good support for XSLT. For styling an RSS feed XSLT 1.0 will do everything you need and that spec has been out for close to 26 years. I don't know what compatibility problems you're expecting.

Typically browser engines that don't support an XML specification version will do the proscribed thing and ignore it. So some old Series 60 WAP browser (were you to find such a thing today) would ignore the XSL stylesheet and display the raw XML or hand it to the registered handler for the content type.

The world went bonkers supporting XML on every computing platform under the Sun for nearly a decade.