I was thinking it would be a collection/comparison of system calls (and/or fundamental userland OS interfaces) across various operating systems. Like what are

I was thinking it would be a collection/comparison of system calls (and/or fundamental userland OS interfaces) across various operating systems. Like what are the different types of synchronous and asynchronous IO in Linux, Windows and BSD, and how do they compare and contrast. A pretty interesting article though, even if it was completely different from what I was expecting.