Thanks for reading. "There is no heap" is meant to say that your mental model of memory shouldn't be one heap from which all memory is pulled. It should be many heaps, owned by many different allocators and providing different semantics. Hence the opinionated stance of the library; there is no allocation function that does not force you to specify the specific heap you want to allocate from. I'm sorry if I didn't explain that well.

As far as the syscall thing, it's actually quite interesting. NT is also extremely stable. Likewise for the stock Darwin syscalls on macOS. In practice, though, Windows loads kernel32.dll automatically, so there's no drawback in using it when appropriate. I still call directly into NT sometimes (mostly to skip complex userspace path translations that aren't useful). On macOS, you are likewise forced to link to libc (libSystem.dylib), and so I usually just end up using the syscall-wrapper libc functions there.