Small and well-factored the core kernel may be, but if you're parsing fonts in kernel mode, you ain't a microkernel.

( https://googleprojectzero.blogspot.com.au/2015/07/one-font-v... )

For sure, and Windows is not a microkernel, but it does have separated kernel-in-kernel and executive layers; it would approach being a microkernel architecture if the executive was moved into userland. This is similar to how macOS would be a microkernel, if everything wasn't run in kernel mode (mach, on which it is partially based, is a microkernel).

Of course the issue here is that after NT 4, GDI has been in kernel mode; this is necessary for performance reasons. Prior to that it was a part of the user mode Windows subsystem.

I'd be curious to see if GDI moved back to userland would be acceptable with modern hardware, but I suspect MS is not interested in that level of churn for minimal gain.

Could you please share a link to NT kernel sources so that I take a look?

It is not true that internal architecture of Linux drivers is not clearly defined. It is just a practical approach to maintenance of drivers (as an author of one Linux hardware driver I'm pretty sure the best possible). Reasoning is outlined in famous "Stable API nonsense" document http://elixir.free-electrons.com/linux/latest/source/Documen...

I don't think Windows approach is worth praising here. It results in a lot of drivers stopping working after few major Windows release upgrades. In Linux, available drivers can be maintained forever.

If you are sufficiently motivated, NT 4 leaked many years ago and you could find it; it even has interesting things like DEC Alpha support & various subsystems still included IIRC. Perhaps you could find a newer version like 5.2 on GitHub or another site, but beware, as a Linux dev/contributor, you probably don't want to have access to that.

FWIW, I've stumbled upon both of those things in my personal research while I had legitimate access to the 5.2 sources as a student. It turns out Bing will link you directly to the Windows source code if you search for <arcane MASM directive here>.

Yes, I'm in the process of reporting this to Microsoft and cleansing myself of that poison apple.

Yes! Windows Kernel is a much more "modern" microkernel architecture than any of the circa-1969 Unix-like architectures popular today. We use Windows 10 / Windows Serve for everything at our company, and we have millions of simultaneously connected users on single boxes. No problems and easy to manage.