Diagrams can produce animations, but currently the user manual is a bit sparse in that area, especially because there are no examples. It ought to be possible to include animations in the user manual, but there are some technical issues to be worked out first.
Here are some notes I gathered at one point (no guarantees they're still up-to-date/relevant):
New HTML5 video tag is cool but there's disagreement over what
codec(s) to support. Ogg Theora was suggested but now isn't due
to concerns about "submarine patents". =(
Looks like the only way to ensure that it works cross-platform
is to encode video in several different formats and providing
the browser a choice.
Looks like a nice JS video player based on top of...
Video for Everybody
HTML specially crafted to make video work as widely
cross-platform as possible: HTML5 video if possible; fallback
to Flash if necessary; and if not even Flash is available it
provides download links.
bash script to prepare/encode videos for use with VFE.
#2 is also relevant.