QNX RTOS uses netbsd userspace applications, actually. And a lot of the drivers in QNX are from NetBSD. It’s more properly a “microkernel” which means the drivers run as userspace applications with a defined interface to the kernel for memory maps to underlying hardware.
Some subset, but even there it's waning, especially for new designs. QNX is seems to be not mentioning it explicitly anymore, and I don't remember seeing it in the options last time I looked, but it's very possible that it is still available if necessary.
Annnnd please let us know how many limbs you had to sell. I'm actually interested in ballpark numbers for this, as I have very fond memories of QNX as the OS where my 100us timers did fire even under heavy IO, threading churn, etc. I miss that.
