Protovis - A visualization toolkit for JavaScript using SVG.
github.com
github.com
The syntax is easy to work with (once you get over the initial learning curve, which is somewhat steep), and it flies on a modern browser. It's the only framework out there for visualization development that's flexible enough to do interesting things with.
I think the only other comparable tool is processing (not processingjs, which is too slow for non-trivial tasks), although processing is focused on pixel manipulation whereas protovis is focused on vector drawing.
and gRaphaël: http://g.raphaeljs.com/
spring to mind.
If you just want Graphs/Charts, here's a few off the top of my head:
http://www.deensoft.com/lab/protochart/
Raphaël does.
This vis library looks really interesting to me because of its flexibility. My main concern is that it's based on SVG. I wonder how easily it could be modified to be canvas based instead. The only reason I say that is because canvas seems to be getting a lot of attention from browser vendors while SVG is languishing...
http://groups.google.com/group/protovis/browse_thread/thread...
I've played around with SVG, which supports links if you use "object" or "embed" tags. But if you use either of those tags, the SVG image acts more like an iframe which has scroll-bars if the SVG is too big, and clicking the link loads the page in the the SVG's little box. If you use the "img" tag then the SVG flows with the page better, but links don't work. :(
It uses native rendering when available, but falls back to a flash plugin that emulates SVG support when it isn't (meaning pre-IE9 Internet Explorer). This ends up covering ~95% of the market.
Also, I'd disagree that SVG is languishing. True, canvas is getting a lot of attention, but SVG is more than sufficiently mature to support projects like this.