[unilynx]

It seems unlikely that Microsoft could ever move Windows over to a different kernel and save on development costs that way, because no suitable kernel seems in sight.

For example the whole Handle and ACL infrastructure has no real equivalent in Linux (at most a bit on the filesystem level) and having to rewrite that for Linux seems pointless and would bring enormous backwards compatibility risks. Office is easy compared to the tightly integrated Windows Server/Active Directory stack.

But that still doesn't mean MS has to invest a lot of R&D in the NT kernel and stack. For userspace they indeed have electron, and on the kernel side they still have Hyper-V, and are even supplying patches to Linux for better integration.

Perhaps eventually Linux and NT will be mostly invoking virtual drivers with the real 'hardware control' work being done in the hypervisors, and the NT Kernel can just be considered 'done'.