knopper's pdf presentations: howto?

I am intrigued by some of the Knopper's presentations found in the 
/Talks/ folder of the Knoppix CD.

They seem to be some kind of powerpoint-like presentation wrapped into a 
.pdf file, which makes them very portable.

Anybody knows where to find a howto manual or web page describing a way 
to produce such presentations?

plasticdoc