[pjmlp]

Please provide an example of an UNIX descendant from Bell Labs implemented microkernel.

POSIX userspace doesn't count, by that measure even an Amiga OS is sundenly an UNIX kernel.

Also a reference CS book in UNIX microkernels architecture would be welcomed.

Even Tanebaum doesn't call Minix 3 a UNIX, rather UNIX inspired.

[monocasa]

Your original post says "UNIX style", not "UNIX descendent from Bell Labs". Don't shift goalposts.

[gpderetta]

OSF/1 counts I think.