Well, there's definitely Ruby support in the Webkit engine these days (as well as in Gecko and Blink); you can do something like data:text/html,<h1><ruby><

Well, there's definitely Ruby support in the Webkit engine these days (as well as in Gecko and Blink); you can do something like data:text/html,<h1><ruby><rb>H</rb><rt>hacker</rt><rb>N</rb><rt>news</rt></ruby> in the browser URL bar to see it at work. Whether iBooks has adopted that in place of your code ... I have no idea.