I enjoyed this a lot. It was very clearly explained and the example was helpful.

I tried to understand XSL back in 2012 when writing Bash scripts to let me download music from Magnatune. They held their catalogue in XML at that time (now it's in a SQLite database) and I used xsltproc and XSL to extract stuff. I didn't find any very clear explanations of what could be done in XSL at that time, though I winged it by copying examples and using trial and error.

Your links seem to fill in many of the gaps in my understanding, so thanks for them too.

Dave