[JasonSage]

I mean, it sounds like his objection is that an operating system that doesn't have POSIX compatibility is dismissed out of hand.

If we think of POSIX compatibility as something which is required in order for an operating system to be viable at any level, it means that there's a lot of energy in pioneering a new OS devoted to building up this compatibility simply so it can get some exposure.

If we really want to encourage a fresh approach and disseminate new ideas, we need to move away from criterion like this and look more specifically at the principles and work being put forth and whether or not those are objectively successful or have merit. That's a much better way to move forward.

[caf]

I think if you were building an OS an an academic research exercise and publishing papers based on it, no-one would object to your results on the basis of a lack of POSIX compatibility.

The criteria is different if you're writing an OS for practical use with wide adoption, though. There, backward-compatibility is rightly considered a positive attribute - there is much existing software in the world, and the entire point of a practical OS is after all to run the software that people use.

Exactly the same situation exists with CPUs. If you come up with a new micro-architecture that you actually want to sell to customers, you'd better come to the party with a C compiler and a ported OS or three.