WinRT on WP8. Did it actually happen?
I've seen lots of people talk about WP8 being based on WinRT for a shared development environment with Windows 8, but I watched the entire presentation myself and I never saw anyone from Microsoft make that claim. Did I miss something?
I saw a slide that detailed the development options for WP8, including C#, C++, and HTML. That certainly sounds a lot like WinRT, but upon closer inspection he's talking about C#/XAML, C++/DirectX, and HTML websites displayed inside a browser control. A browser control isn't even remotely the same thing as the deeply integrated HTML5 development option provided by WinRT, and there doesn't appear to be a C++/XAML option either.
Ignoring how anyone feels about the importance of C++/XAML or HTML5 development options, it certainly suggests that WP8's SDK isn't based on WinRT. Since Browser controls have always been available in Windows Phone, this slide is actually describing WP7 development with a native C++/DirectX option added on.
They also said specifically that if you want to develop for both Windows 8 and Windows Phone 8, you should use the C#/XAML option on Windows 8. That's identical to the advice they've given for WP7. If WP8 was really running the same WinRT framework as Windows 8, then why would it matter which development option you chose? Anything that runs on one should just run on the other, right?
For what it's worth, they did say that the APIs are the same across Windows 8 and Windows Phone 8 for native code. If you're developing a game with C++ and DirectX, then some minor tweaks should be able to make it run on both. That's a big plus, but I never saw them make a similar claim for non-game apps.
I think all their talk about the "shared core" and the API sharing for native code led everyone to jump to conclusions. Remember that iPhone and OSX share a core, as do Android and Ubuntu, but that doesn't mean that developers can target both OSs at once because they run different application frameworks.
Everything I saw at the presentation suggested that Windows Phone 8 is still based on Silverlight. They never mentioned Silverlight by name, but they never mentioned WinRT either. I'd love to be wrong here, so if anyone has conclusive evidence that Microsoft has announced WinRT for WP8 I'd be happy to see it.