@p @dcc @Maholmire @pwm @dushman @nerdeiro @BrodieOnLinux @mima @SrEstegosaurio @Hyolobrika microkernel only has to conceptually be separated into components and communicate with message passing but it's possible to do this without enforcing the boundaries. I believe QNX is like this, you can bypass message passing but don't do that! Your software won't crash because you followed the rules. Until you fail to validate untrusted input. But in practice you want to enforce the boundaries. That has security benefits but mainly it's about reliability. component crashes. it's a mini-server with defined input and output, no shared memory. you just restart it.