Basically I want to build a web interface to a server-side math engine. (Like a simplified version of QtOctave/GSL.) But I haven't seen many resources to generate mathematical graphs on the client side--bar plots, heat maps, etc. Support for this even in HTML5 seems to be lacking, as this short discussion suggests. Is there any web equivalent to Qwt, jCharts, etc.?
What about Protovis?