To be fair, when XML was cool, XSL did a good job in carrying out templating-language-like-features. Use case was like: Write semantic XML document, use XSL to generate XHTML, render XHTML in browser. Modern browsers still run XML with XSL.
I still use browser-side XSLT in my apps. Google had threatened to remove support but there was much pushback from the enterprise community that has many business apps using that approach so Google backed down. Still no guarantee that they'll pull the plug in the future.
