[KMag]

Anyone have any idea why there haven't been any open-source QNX clones, at least not any widely known ones? Even before their Photon MicroGUI patents expired, the clones could have used X11.

I used to occasionally boot into QNX on my desktop in college. It was a very responsive and stable system.

Hypervisors are, to a first approximation, microkernels with a hardware-like interface. All of this kernel bypass work being done by RDBMSes, ScyllaDB, HFTs, etc. is, to a first approximation, making a monolithic kernel act a bit like a microkernel.

[fulafel]

There are well known open source microkernels, like Minix 3 and L4. Probably not that attractive.

Why something hasn't been done is always a hard question to answer, since to succeed a lot of things have to go right, and by default none of them do. But one thing is that microkernels were more trendy in the 90s - r&d people are mostly doing things like "the cluster is the computer", unikernel, exokernel, rump kernel, embedded (eg tock), remote attestation since then (I'm not up to date on the latest).

[KMag]

Thinking about it a bit more, QNX clones might suffer from something akin to second system syndrome. There's a simple working design, and it likely strongly invites people to jump right to their own twist on the design before they get very far into a clone.