If you are thinking of using XML and XSLT in a web-server environment, perhaps you can check out AxKit and Sablotron. AxKit is build upon mod_perl in the Apache-webserver. Sablotron is written in C but has also a Perl-interface.

I have used it to transform Perl-generated XML into HTML.

CountZero

"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law