Really cool, but the examples don't work well for me. One scroll step with my mouse on Windows is enough to scroll past some of the intermediary animations. A lot of information is lost because of that. I have to slowly drag the scrollbar with my mouse to view all animations. Another thing that has been pointed out is that this needs to degrade gracefully for PDFs and printed media.
It does not. I can't remember the last time I printed out a tutorial video. Just because this media describes itself as 'animated technical papers' does not mean it should behave like dead-tree or static pdf technical papers any more than 'motion pictures' should behave like tintypes.