Terminal: make Windows Terminal available to v1809

[fredless]

Summary of the new feature/enhancement

There are a significant quantity of corporate machines not able to run 1903 today for a variety of reasons (policy, compatibility, etc) and hence are locked out of terminal. I wasn't able to find much discussion about the reasons that exist for 1903 to be a requisite.

[JushBJJ]

In my guessing, there is probably a feature within the windows source code that is used in the new terminal which is why 1903 is required.

[ysc3839]

I guess it's because maintaining compatibility is a trouble. You CAN try to run on 1809 but without any support.

[DHowett-MSFT]

Sorry. Right now, there's two big blockers to adoption on 1809.

• XAML islands was a technology preview and didn't support high-DPI, DPI changes, or accessibility in 1809. We rely on them heavily.
• 1903 added support for side-by-side WinRT component activation, something deep in the COM stack that lets us find our DLLs when they're right next to our EXE.

We just can't go back to 1809.

[fredless]

We just can't go back to 1809.

TY for the detail

[brunofin]

We just can't go back to 1809.

Please Microsoft, fix the Surface Book 2 then so we can upgrade! 😭

[NetMage]

It looks like WInUI 3.0 will backport full XAML Islands support to most versions of Windows 10 and is releasing this year - could you use WinUI 3.0 to add support for Windows Terminal on earlier versions of Windows 10?

[zadjii-msft]

That's certainly a possibility we'd have to investigate. If XAML Islands was detached from the platform, then I'm not sure how many of our own features are actually dependent upon 1903.

I guess Dustin mentioned the SxS winrt activation above - I'm not _positive_ that is still needed, but if it is, then that might be exceptionally hard for us to overcome. That would be one of the things to investigate when WinUI 3.0 is available.

[superm1]

WinUI 3.0

It seems to me that there is now a preview available for it: https://docs.microsoft.com/en-us/windows/apps/winui/winui3/

[zadjii-msft]

XAML Islands is not supported in this release

That's the single most important part of the WinUI stack we need, so unfortunately, that's a non-starter for us. Don't worry, we work pretty closely with the WinUI team (in the same hallway in fact), so when WinUI 3 is ready for us to move to it, we'll work on it 😉

[sidietz]

WinUI 3.0 Preview 2 has been released some days ago. Anything new on LTSC support?

https://docs.microsoft.com/en-us/windows/apps/winui/winui3/

[superm1]

Seems to still quote "XAML Islands is not supported in this release" on the preview 2 release notes.

[DHowett]

I've gone ahead and marked up their list of limitations with ones that stop us from being able to use Preview 2:

[zadjii-msft]

As I've said before, we won't be able to start experimenting with WinUI 3.0 until there's support for XAML Islands.