Note that the part where I mentioned kernel and safe used quotes because its sarcastic. The modern oses do have kernels that are much safer than what we use da

Note that the part where I mentioned kernel and safe used quotes because its sarcastic. The modern oses do have kernels that are much safer than what we use day to day, however. They're indeed not in C. In general the core is typed ASM and it runs a a managed language right on top. The kernel is generally written with that and uses various concepts that separate privileges as much as possible for security, reliability and predictability, basically. That includes kernel components, and obviously drivers. Messages between components are also generally declared ("contracted") with well defined types.