I think it's the same UIWebKit. If you're willing to Jailbreak your device, you could take a look at the files and find out. The issue is that no apps other th

I think it's the same UIWebKit. If you're willing to Jailbreak your device, you could take a look at the files and find out. The issue is that no apps other than MobileSafari can do JIT compilation, due to security constraints put in place by the kernel. You can't write to a segment of memory and later make it executable. To pull this off with MobileSafari, I suspect that Apple put a back door in the kernel, and requires apps to be signed with a specific entitlement to get access to it. And I'm guessing that MobileSafari is the only app with this permission. For full screen web clips, it might be possible for Apple to give the wrapper the right permissions without breaking their security model. Hopefully they do this in the future. But I doubt that 3rd party native apps will ever be given the ability to modify code.