The guys over at 280 North (who built the awesome web app 280 Slides) are working on an app very similar to Apple’s Interface Builder, but for web-based applications.
It is VERY impressive work, and I highly recommend watching the video. I am still on the fence about Objective-J, though. It’s just so different from all the other languages! But because its similar to Objective-C, which is used for iPhone apps, it might have a chance of catching on.