a) there are microkernel-based operating systems that are available right now. QNX and Green Hills, for example. There aren't any free ones that I know about, s

a) there are microkernel-based operating systems that are available right now. QNX and Green Hills, for example. There aren't any free ones that I know about, so the cost might be hindering adoption. b) agree with you on this point that monolithic is 'good enough' these days. There are specific benefits to my particular application, but for a general desktop user I don't see the point. Even on a server the benefits are not very visible.