You have to decide for yourself what is relevant to your application-visible needs. If you deem that Linux is better for running your Java app than QNX, no one

You have to decide for yourself what is relevant to your application-visible needs. If you deem that Linux is better for running your Java app than QNX, no one wants to take that decision away from you. I don't think that's where the real discussion is. The real discussion involving microkernels is about the future of OS development. Should it just be the same as Linux, forever, with no architectural changes? Have we literally written the last OS? As a layperson, I can be persuaded microkernels are a good idea that could yield some reliability and security improvement. I can be persuaded that the performance issues are avoidable. But I'm also pretty sure that most of the problems we have with current systems are in code that would now be outside the microkernel anyway. We are going to end up with, optimistically, about the same number of lines of code. So to me it seems much more important what the development process looks like. Unfortunately there is not a lot of accessible research about that kind of thing, relative to things like microkernel performance which are at least easy to generate demonstrative benchmarks for.