XSLT definitely has its flaws and I'm not currently using it, but I am currently building an app whose UI is heavily data-driven, meaning a screen might display a dynamic list of items, each with a totally different editing/viewing/previewing experience. You can dance around the edges of this with current templating engines to the point where you have a workable solution for a specific case, but honestly nothing really compares to the generalizing power of template matching where all you'd need to do is wire up the appropriate XPath selector to a new template and there you go. This level of abstraction does not even appear to be on the radar of the templating libraries I'm familiar with but I'd love to hear about those that do support it if they exist.