But it's not being used there in current mainstream production.
https://www.meaa-mea.com/advanced-mobility/
https://www.blackberry.com/us/en/success-stories/mitsubishi
It's certainly difficult to pick through the Blackberry QNX hype to see where it's actually headed outside of infotainment, lot's of fuzzy weasal phrasing:
https://blackberry.qnx.com/en/industries/connected-autonomou...
Outside of some vague blackberry press materials, I've never seen anything specific.
Outside of some vague blackberry press materials, I've never seen anything indicating use in vehicles.
Or could they work if only people would stop focusing on Hurd? Is Hurd a dead end? Or is GNU the real problem and should we abandon that?
Out of all of the microkernels out there, the one I like the most is SEL4, but the security model is so different from most OS kernels that you essentially have to program for it from the ground up. And it seems like there isn’t any momentum there either. QNX is already very mature and performant though, and it has gotten a huge boost from IoT and electric car development, and IMO all it needs is an open source license and it will eventually creep its way into general purpose OS usage.
Yes, it's old. Yes, there's only little interest. Yes, there are _still_ many technical problems.
The interesting thing here is that technical problems can be solved, and will be solved given enough time. Heck, I've heard rumors that even Windows does not crash multiple times a day anymore.
Focussing and working on what is popular will most likely create a world that is less free every year. Some people rather work on something that seems right and promises a better, freer future. Even if it's not popular (right now), even if it has a high probability of failure.
Popularity is a very volatile property...
And popularity might be a double edged sword, but double edged swords are still useful if you're careful.
Although keeping software proprietary or writing proprietary software may have become somewhat unpopular in some niches (I'm not sure it's incredible unpopular seeing how many people and institutions still use and often advocate Apple, MicroSoft, use FaceBook, WhatsApp, whatsnot...), I'm not yet convinced that many people (say more than 1%) really believe that all software should be free and act on that?
They (microkernels) thrive in Automobiles, Aircraft, Spacecraft, Security systems (such as hardware encryption devices), Defense Munitions, Embedded Devices, Maritime devices, radar systems, and many other areas. The common thread here is that they are not just resource constrained and performance sensitive, they are also typically very specialized and mostly write-from-scratch.
That last part is the key to understanding why general purpose operating systems mostly use legacy kernels that are decades old. We want to preserve as much as we can from what came before.
> But why is Linux the incumbent when Mach and Hurd were conceived 3 years earlier?
Because Linux worked earlier. Nobody in the GNU ecosystem knew how to develop a microkernel that worked, let alone drivers for a constantly changing target OS.
> I would love to believe that, but then why has that advantage not paid off for 30 years?
Again, they have. Almost all RTOSes are microkernels, and the most popular embedded OSes are microkernels. When you're writing something from scratch, it is always going to be easier with a microkernel. Don't mistake Hurd with the concept of a microkernel. Hurd sucks because it has always sucked. It's bloated, poorly documented, relies on a very janky GNU ecosystem that has already mostly adapted to Linux out of practicality concerns, and there is no ecosystem tooling around it.
But the advantages of microkernels in general are very real. The best one out there in terms of maturity is QNX, and while practically every modern car on the planet runs on it, it's licensing pretty much precludes it from being used as a general purpose OS.