[pjmlp]

Quite a few embedded OSes are microkernels, L4 being one of them.

[disordinary]

Interestingly L4 is being used to power the secure enclave on iOS devices so it's probably the most distributed microkernel.

[lokedhs]

There was a plan to move Hurd to use L3 instead of Mach, but apparently that project was cancelled.