A clever dev has managed to shoehorn full-blown iOS apps onto the BlackBerry PlayBook tablet. Such App Store titles as Tiny Tower, Super Monkey Ball, TomTom Navigation, Sushi Cat, iFart, Frogger, Galcon, SketchBook, and a few others. Oh, and the iMore app, of course. This has been made possible through a kind of iOS player that a developer has managed to get to work on Windows too. The dev has gone into a few technical details as to how they've pulled off this feat.
The CPU isn't emulated on Playbook (though it is on Windows). It works very similarly to how WINE works to run Windows applications on Linux. The app binary is mapped into memory and imports are resolved to point to my own implementation of the various APIs needed. iOS actually uses a few open APIs already, which Playbook supports just as well (GL ES, and OpenAL). The bulk of the work has been in implementing all of the objective C classes that are required. The ARM code of the applications run as-is - the armv6/v7 support on PB/iDevices are pretty much identical, and the code is designed to run in USR mode. No SWIs, GPIO accesses or any of that kind of shenanigans.
Obviously, this is all well outside Apple's interests, but it may be within RIM's; after all, they made lots of accommodations to bring in Android apps into the BlackBerry ecosystem, and though there's no direct porting of iOS apps, RIM has generally been good about getting cozy with middleware providers that also happen to support iPhone and iPad apps. There's still a lot of work to be done in the emulation environment, so don't expect anything soon. Even if it's polished enough for the public, the dev says "I would like to release to the public, but not sure if I will be able to."
Although the solution to do this isn't publicly available, it poses a fairly grey area for users. During the hayday of PlayBook rooting, there were lots of leaked versions of Android apps floating around, some paid, some not, and if this solution ever goes public, we would likely see a similar boom in app piracy. Those that picked up a PlayBook while it was cheap would be happy to get a bit of added functionality out of it, but I doubt anyone will go after a PlayBook or a BlackBerry 10 device for its iOS app support - just get an iPad, or if you're really married to the 7-inch form factor, hold out for the iPad Mini.
As someone who has put a fair bit of time into the PlayBook, I find it's impressive that the development environment is proving to be this flexible. I was always a fan of the bezel gestures on the PlayBook, and despite all the bad press, the app ecosystem is starting to pick up. Heck, BB10 might even get Jetpack Joyride before Android. What do you guys think the prospects are for BlackBerry 10 and the PlayBook in light of iOS 6? Will RIM actually be able to rope in developers?