You might remember the Apple Newton, Apple’s earlier PDA that never really took off. The OS has been resurrected via an emulator running on the iPhone 4, effectively giving you an Apple Newton on a sleek modern body. If you check out the video (after the jump), you’ll notice that it’s running a little sluggishly, but the developers state that the speed will be improved. Via emulator, the whole system is running properly, complete with handwriting recognition. Of course, with iOS on the iPhone 4, you don’t have any real use for the Newton, but it’s still a cool achievement. In case you want to tinker with this setup yourself, the source code is available for download.