Some XSLT processors (XSLTC for example) compile stylesheets into Java bytecode (or equivalently, other intermediate codes such as CIL on .NET). I believe the technique is also used by some XQuery processors. Some users assume that a product that compiles to bytecode will be necessarily faster than an interpreter. I've tended to argue that high-level optimizations are more important, and that compiling expressions to bytecode might reduce the scope for high-level optimizations, if only by making them more complex to implement and debug. I set out today to do some experiments....   more »