[TUHS] Is there a good, even definitive, list of reimplementations of the Unix kernel? What would good cut-off criteria be?

[Peter Yardley via TUHS]

Hi,

OSX uses a microkernel, Mach. Thing is more and more code got moved from user space into the kernel to speed it up. First OSF1 moved more code into kernel space, then NeXT, then Apple. But the kernel definitely started out as the Mach micro kernel.

> On 19 Apr 2026, at 11:16 am, John Levine via TUHS <tuhs at tuhs.org> wrote:
> 
> According to steve jenkin via TUHS <sjenkin at canb.auug.org.au>:
>> Was “Wind River” and its VxWorks “Unix-like” or something else?
> 
> Something else, I think.  They bought BSDI to get a Unix system.
> 
>> Does GNU count, as their HURD kernel has never attained the attributes necessary for wide use?
> 
> HURD lost its reason for existing once linux worked since it's also GPL.  I see people poking
> at HURD, but nothing serious.  Microkernels are an idea that looks appealing but has never really
> worked because they're slow due to all the process switching.
> 


.1.3.6.1.4.1.8852.4.2
Peter Yardley
peter.martin.yardley at gmail.com