[ggchappell]

> Continuing in the "let me Google that for you" vein, both QNX and various L4 family microkernels are in use in a variety of embedded systems; QNX is also in the new Blackberry products. There's a number of very mature security oriented research microkernels (like L4se and K42) that could very well show up in commercial products eventually. But that's back to needing to know more about computer science than Windows and MacOS.

Let's be fair here. Your claim was that microkernels are "in general use". Ongoing research, however mature, does not support this claim. And Blackberry is hardly the heavy hitter they used to be. Meanwhile, the major OSs for computers as computers -- and as phones -- have backed away from the microkernel design. Maybe they shouldn't have; regardless, they did.

That leaves embedded systems. And there you have a point. So: microkernels are in common use in embedded systems. But let's not overstate their successes.

[jacquesm]

Let's be fair here, embedded systems are computers like every other and there are far more of them than there are regular computers. If you walk into any slightly larger production plant and you take QNX and other soft real time or hard real time controllers out then that plant becomes so much scrap metal.

Besides, QNX works very well on PC hardware and is used extensively in the communications industry.

Please do not take your own limited exposure to the world of IT as proof that certain things are true, especially when they are emphatically not. I know of several thousand QNX installs within 10 km from where I'm sitting.

Denying the success of micro kernels such as QNX by disqualifying applications is like claiming linux is a failure by excluding mobile devices.

[kjs3]

Let's be fair here. If you get to redefine "computer" to exclude embedded systems, even though they vastly outnumber "computers as computers" (whatever that really means), then you get to be right. But really all that does is show your limited view of the the field. For example, QNX runs 10s of millions of cars alone and who knows how many Cisco routers running IOS-XR. If that is "overstating" success, I'm not really sure what success looks like.

[ggchappell]

> Let's be fair here. If you get to redefine "computer" to exclude embedded systems, even though they vastly outnumber "computers as computers" (whatever that really means), then you get to be right.

Actually, I don't think I disagreed with you, except to note that a research kernel that might be used someday, does not count as "general use".

You might count the insinuation of overstatement as a disagreement. The point of that is that context matters. When I talk about choice of OS, the Mac in my living room has rather more weight in my mind than the embedded controller in my garage; I know I'm not alone in this. So if we say only that microkernels are heavily used, then we are correct, but we will be misunderstood. It is better, I think, to make a statement that is both correct and understandable, than to make one that is merely correct, while looking down on those who misunderstand.

EDIT: A quote[1] from me, giving an example from a rather different topic:

> If I open up a restaurant that serves General Tso's chicken and chop suey and sweet and sour pork and fortune cookies, and I advertise that I serve "American food", then my description is accurate, but my customers will be confused.

[1] http://www.reddit.com/r/todayilearned/comments/25dji0/til_ge...

[kjs3]

> When I talk about choice of OS, the Mac in my living room has rather more weight in my mind than the embedded controller in my garage

This is pretty much exactly what I'm selecting against. It's not that your concept of "general use" in computer science excludes embedded systems (frightening, considering you're apparently teaching this stuff). It's that when more than one poster tells you that you're wrong, and provide concrete examples of why, your response isn't "that's something I need to consider" or "perhaps my knowledge of the field isn't what I thought it was" or best "I've got more to learn". Nope, you decide the "context" of the discussion is whatever you want it to be and to trot out a contrived bit of sophistry which boils down to "I might be wrong, and I'm not saying I am, but because lots of other people would be wrong, I get to be right". Or something. Doesn't matter. We weren't opening a restaurant.

Double bonus points for focusing on a throwaway, tangential comment and pretending it's a central flaw of argument. This clearly isn't your first specious Internet argument.

[ggchappell]

Well, then, I suppose your comments are something I need to consider.