With a hell of a lot of thanks to Nick Gressle’s (@nick) post describing how to embed a Hype document into an Xcode app, I was able to at last crack through Apple’s walled garden with a spooky woo-woo program called Pentacaster. The app uses the HTML Canvas object to do its actual drawing; everything else is happening in Hype.
More amusingly, perhaps, the page where the preview is located — as well as my entire current website — is Hype generated. Because life is far, far too short to waste on hand-coding anything in TextWrangler (good though it is).