Comment by 013a
7 years ago
Google is doing this, very publicly, with Fuchsia. Brand new kernel, not even POSIX compliant.
Microsoft is also doing this, in a different and substantially more expensive way [1]. Over the past several years they've been rewriting and unifying their disparate operating systems (Windows, Phone (before the fall), Xbox, etc) into a single modular kernel they're calling OneCore. Its more than likely that this work is based off of, if not totally contains, much of the NT kernel, but its the same line of thinking.
There is one massive rule when it comes to engineering management we see repeated over and over, yet no one listens: Do Not Rewrite. Period.
Apple is exemplary in this. We don't know how many changes they've made to iOS since its fork from MacOS long ago, which was based on BSD even longer ago. But have you used an iPad in recent history? Instant app starts. No lag. No-stutter rendering at 120fps. When HFS started giving them issues, they swapped it out with APFS. Apps are sandboxed completely from one-another, and have no way to break their sandbox even if the user wants them to. Etc. Comparing an iPad Pro's performance to most brand new Windows laptops is like fighting a low-orbit laser cannon with a civil war era musket. They've succeeded, however they managed to do that.
Point being, you don't rewrite. You learn, you adapt, and you iterate. We'll get there.
(And if you've read all this and then wondered "but isn't Fucshia a rewrite" you'd be right, and we should all have serious concerns about that OS ever seeing the light of day on a real product, and its quality once that happens. It won't be good. They can't even release a passable ChromeOS device [2])
[1] https://www.windowscentral.com/understanding-windows-core-os...
onecore isn't really about the kernel, but the intermediate layers above it.