Ask Paul: October 4 (Premium)

Hot off this week’s Microsoft event, here’s an epic Ask Paul to celebrate the start of the weekend.
Windows 10X, OS modularity, and you
Dan1986ist asks:

Will Windows 10X running on top WCOS herald a change in how Microsoft and OEMs do Windows 10 on device form factors going forward, if it is successful, or will be another RT or Windows 10 S?

That’s the million-dollar question.

First of all, what’s happening here isn’t all that new, it’s just an evolution of the (NT-based) Windows modularization efforts that Microsoft has been engaged in for almost 25 years. I’m kind of amazed how this is presented as something new fairly regularly (during Longhorn, for example, or during the “One Core” days). But you can go back further than that: Windows CE, from 1995, was such a product.

What is sort-of new this time around is that the modularization is taking place in two different places in the stack, whereas previously Windows was modularized into horizontal slices that each built on top of each other. But with the current modularization effort that resulted in both Windows Core OS (WCOS) and Windows 10X, the architecture is now split vertically as well so that different Windows product editions can, for the first time, support different shells (user interfaces). This architectural diagram, created by Mary Jo Foley and reflecting Microsoft internal documentation, demonstrates what I mean.

What makes this different and better than Windows RT, Windows 10 S/S mode, and Windows 10 on ARM is that the system can run all legacy Windows desktop applications, not none (RT/S mode) or just some (W10 on ARM) of them. Microsoft hasn’t discussed this publicly yet to my knowledge, but it is using a container-based approach, which many theorized was coming, to accomplish this. The result is a lighter core OS---thus explaining the Windows 10 Lite codename---that can run on less expensive hardware.

What’s confusing about Windows 10X is that Microsoft is specifically targeting dual- and folding-screen devices only for some reason. My understanding is that Windows 10X will later be adapted to work on traditional form factors as well and that this platform will become the mainstream Windows version over time. Mary Jo happens to believe that Microsoft will split the platform again vertically, creating yet another Windows experience (or what I called “personality” in What the Heck is Windows 10X?).

The specifics aren’t important. What we see here is a modern take on the Windows platform that could finally move Microsoft and its user base past the messy, insecure, and unreliable Win32/desktop application platform. We’ll see how that pans out.

kshsystems adds:

If the win32 legacy is being containerized, do we know what the modern API is that MS is targeting?

I asked this question to multiple people at Microsoft and was told that the developer story will emerge publicly in the next few weeks. My understanding is...