WinRT is not .NET but C++ based target (but using interfaces afaik, a bit like DirectX is styled, api wise) we first would need a FPC port to it. It is not "win32/64".
And in other words is possible?
In theory yes, but as said it is a whole new target. The devil is in the details (think stuff like exception handling etc). And some of the target specific stuff will need to be repeated for other architectures (read: ARM)
Also I don't know much about the practicalities, specially related to codesigning:
- will Windows will run unsigned or self signed winRT binaries?
- how to deploy? Can you execute win RT binaries outside the store as an user?
- Probably you can do the above as part of a developer program , but what does that cost? Is it doable for interested FPC users, or do they require Eur 100 an year or so. That would limit the audience tremendously.
Interested are encouraged to search the forum and the fpc-devel and lazarus lists. IIRC Sven did some research about this and answered some of these.
Note that this is the first interest in WinRT in say 1.5 years........ That says almost enough in itselfl.