&gt; The XHTML+XSLT+XML-FO stack produced pages that took 3x-10x less CPU to render. But that&#x27;s dead of course.<p>Was it ever alive? I never found a decent browser XSL-FO renderer, there were some that seemed kind of proof-of-concept-ish (the only decent XSL-FO rendering I ever encountered was intended for print-like media, mostly PDF, rather than for browsing.)