Once upon a time I was deeply in the world of XML Schema, XSLT, and XQuery. It was actually pretty cool. But using complex, poorly specified, possibly Turing-

Once upon a time I was deeply in the world of XML Schema, XSLT, and XQuery. It was actually pretty cool. But using complex, poorly specified, possibly Turing-complete "config" files written in a markup language that isn't the primary language your app is written in is a serious code smell. It means you would either be better off using an embedded scripting language (like Groovy) or a better core language.