I’m really not sure what I said that warranted this reaction.

I was literally talking about Microsoft moving the compositor that was inside the kernel in their old Windows 9x kernel architecture to outside the kernel in Windows NT.

That literally every other kernel (OSS and comercial, Unix and not) does this separation suggests this is a generally accepted good security practice.

I’m not aware of any kernel research that alters the fundamental fact that having compositing in-kernel compositing is a big security risk surface area and the OS you are proposing isn’t even pure Rust - it’s got C and assembly and unsafe Rust thrown in which suggests there’s a non trivial attack surface area that isn’t mitigated architecturally - AFAIK capability security won’t help here with a monolithic design and you need a microkernel design to separate concerns and blast areas to make the capabilities mean anything so that an exploit in one piece of the kernel can’t be a launching pad to broader exploits. This is also ignoring that even safe Rust has potential for exploit since there are compiler bugs around soundness in terms of generated code so even if you could write pure safe Rust code (which you can’t at the OS level) a monolithic kernel would present issues.

TLDR: claiming that there’s decades of OS research to improve on that existing kernels don’t take advantage of is fair. Claiming that a monolithic kernel doesn’t suffer architectural security challenges, particularly with respect to compositing in-kernel is a bold statement that would be better supported by explaining how that research solves the security risks rather than launching an ad hominem attack against a different kernel family than I even mentioned is just a weird defensive reaction.