ahhh, XSLT, haven't heard that name in awhile.

For my CS honours thesis, I created XSLT debugging program - my research paper is here

http://ww2.cs.mu.oz.au/~jbailey/papers/wise.ps

I miss it :) but now that I'm doing lots of web development & javascript, I do wonder that it is somewhat "slow" or "heavy" than other approaches.

Nonetheless, it was an awesome experience diving deep into the technology.