Just to weigh in with the rest here, I recently gave a presentation for
the Columbus LUG (http://www.colug.net/) about Debian, and being
frustrated with the existing presentation software in Debian, I wrote my
own. I'm planning to turn it into the XML Presentation Library, similar
in spirit to the XML Résumé Library. It currently only generates XHTML,
but XSL-FO is next (which can be translated into PDF).
The current source code is in the directory of my presentation:
http://web.verbum.org/~walters/files/colug/
You can see some sample output here:
http://web.verbum.org/~walters/files/colug/debian.html
Let me know if you're interested in it :)