Yes. I work with QNX6.6 daily. I also worked with QNX6.5 and QNX7.0. It's a real blast to work with the mikrokernel. It's a really cool system, and the kernel stability is excellent. Feels good that when a low level driver crashes, your system just goes on as if nothing happened (except, of course, the applications that need this driver). Speaking of drivers, the driver situation on QNX is a bit sad, simply because there are few drivers and the ones that exist aren't as high quality and well tested because QNX is niche. Still, if there was a QNX environment that is as progressive as Linux Ubuntu (concerning GUI, drivers, etc.) and OpenSource, I'd definitely use QNX as my main OS.