It goes well beyond being well liked. For us - mid sized company, building a very large message switch for the shipping industry - it was an enabling technology. I don't think we could have built the product at all without using QNX as the foundation. It got us about as close as we could get to Erlang like concepts while not breaking the bank and with a toolset that we already knew how to use. That system broke record after record every Monday morning for two decades before some new PM decided that it all had to go and be replaced by Windows. I don't think that system ever saw the light of day, but I could be wrong, I left shortly afterwards.
Back in ?1990, I was working on a collaborative project for multivariable control for heating and blowing plastic bottles. I think I was writing the back end, and a colleague in Germany was writing the front end, both to run on the same QNX system. The back end could be written in ANSI C, but the windowing system required K&R C. We didn't have email connection, so the only way to coordinate development was a write down an integration interface, develop to that, then head over to Germany holding a floppy disk. The thing was up and running in five minutes. Very nice OS to work with!
QNX powered so many success stories it is interesting how it stayed almost entirely hidden from those that weren't directly working with it. The joke went that if you removed QNX from the planet we'd die within a week. I'm not sure if that isn't still true to some degree today because so much infrastructure runs on it and that stuff lasts for decades.
Back in the 2000’s we built a complete network operating system on top of QNX for OTN based long haul communication systems. In those days we had to sign SLAs on equipment and customers fined us for downtime. QNX was bulletproof despite running on our then PowerPC based custom CPU complex.
