Just prototyping? Is the plan to throw it out and use something else for production? Why?
I'm hoping that the prototyping can lead to Racket being the tools and authoring platform.
Racket is a great environment for developing DSLs and graphical tools.
http://hashcollision.org/whalesong/
It's a Javascript VM that interprets Racket bytecode. It's complete enough to run, eg. World/Universe games or render HTDP2e pictures. Might be useful for some of what you're doing.
I thought that Whalesong was a Javascript code generator rather than a VM ?
Unfortunately JS performance on iOS rules that out for our purposes.