Pretty promising project over at PhobosLab of the Impact Game Engine running on the iOS platform using the JavaScriptCore Framework. The best part is it has all Canvas calls passed into run on OpenGL ES thus the speedy demo.
Biolab Disaster on the iPhone 3GS from Dominic Szablewski on Vimeo.
The game is running in its own process and is not using the iPhone’s browser at all. Instead, it’s just using the JavaScriptCore Framework to run the game. All the necessary calls to the Canvas API have been reimplemented with OpenGL-ES and the touch input is passed over to JavaScript to be evaluated by the engine. I of course had to make some changes to the engine, but the game source code is exactly the same as for the web version.
This would probably never fly on the App Store because it executes code or interprets it but is a very nice experiment. More discussion at Hacker News..