Except, you are not really getting it. I am talking about something new, and completely undiscovered. You know, technology moves on. There WILL be other ways of running Windows apps in OS X in the future.
David
I get it, but you don't quite get how computers work... the technology may /improve/ but it still must fall into one of the three categories above.
Classic is a virtualization technology, for example. Rosetta is sort of the opposite of API Emulation, where the APIs are the same, but you need to translate the executable (and doesn't apply to a situation of Windows on OS X).
The 'problem' of running Windows apps on OS X is actually pretty simple one at a high-level, but horribly complicated in implementation.
You have an executable file (app.exe) that you want to run. It differs from an OS X executable (app.app) in two ways:
1) The format of the file, and how code, data, and links to libraries work.
2) The sets of libraries that it links against, and how it talks to the OS.
#1 is relatively easy to solve. It has been solved numerous times. #2 is the harder part. How do we handle #2?
Well, we can replace the libraries themselves (API Emulation). Wine already does this, but doesn't do it very well, and there are so many APIs that it is a fool's errand to take this route. But the up-shot is that you can make an app run natively in OS X without the need for Windows at all. Odds are that compatibility here will be horrible.
We can replace what the libraries talk to (can be both API emulation and virtualization, depending on the tactic used). However, this is VERY tricky, as an OS tends to be huge. Drivers in the Windows kernel define new interfaces that libraries talk to. So, not only are you trying to write a new kernel that runs on top of OS X, but you need to emulate all the drivers a Windows system might need. You won't get 100% app compatibility this way, either. It also requires that you copy files from Windows itself to work.
We can just take the libraries, and everything attached to them, and run them in a box. This is virtualization. With a little more effort (custom drivers, and the like), we can make virtualization seem pretty native, a la Parallel's coherence mode. This requires files from Windows to work, but it is also the best way to get near-100% compatibility.
It isn't like there is some magical way to break out of this. Classic was interesting because it used virtualization in a new way to make apps seem native. Rosetta is interesting, but at the same time, not much different from the old 68k emulator during the PPC switch.
There are lots of different ways to interpret and attack this problem, but in the end, it is all some form of Virtualization or API Emulation (or even a hybrid). Yes, there will be new ways to run Windows on OS X... but they will all be evolutions of the core principles (just like we get new programming languages, but they are still built on the same core principles and building blocks as all languages).
