I wrote an XML-based language in Java years ago. It worked a bit like Rails macros, allowing arbitrary Java classes to be instantiated and their results displayed in a web page.<p>In my defense, this was in the late 90s. There was not much out there for not-completely-ugly web development. It actually worked pretty well. It let us write our business logic in POJOs and then rapidly code up XHTML web pages with embedded XML tags to invoke these and display the results. It was also pretty fast. The alternatives were crummy old PHP3, a bunch of proprietary junk that was mostly worse than PHP, and servlets full of out.println("<tr><td>"+var+"</td><td>"... madness.<p>But apparently it's still in production. That makes me shudder, since there are <i>much</i> better things out there now.<p>Edit: just checked. Finally, it appears to be dead. Heh.