This, d3, etc. all look extremely cool and like great ways to do procedural graphics creation / animation.
Has there emerged yet a Flash Builder-like tool for Canvas-based web graphics yet? I feel like there's a fundamental limit to how widespread procedural graphics production will be since many designers/animators/game developers a just don't work that way -- they need visual tools. Or so I assume.
http://html.adobe.com/edge/animate/
They also are working to allow you to export Flash to Canvas through what they call Flash Professional Toolkit for CreateJS.
CreateJs is a better solution, but you still need canvas ( you can still polyfill with flash canvas for older browsers )
It's primarily focused on animation and video. Published animations use the Canvas tag instead of SVG. (I'm not a huge fan of SVG for this kind of rendering because it's such a sprawling committee-designed document format rather than a compact and expressive API.)
Radi is currently Mac-only. I had a Windows port underway at one point (to the point of actually getting the app running on Win7), but haven't had the time to work on it lately... Hopefully it'll be on Windows too one day.