John Carmack's arguments against building a custom XR OS at Meta

And yet, Sony did it, Nintendo did it, both have been pretty succeesful.

We also need to be clear what an OS is. Is it "darwin" or "macOS" - they have different scopes.

Things I'd want from an OS for an XR device.

1. Fast boot. I don't want to have to wait 2-3-4-5 minutes to reboot for those times I need to reboot.

I feel like Nintendo figured this out? It updates the OS in the background somehow and reboot is nearly instant.

2. Zero jank. I'm on XR, if the OS janks in any way people will get sick AND perceive the product as sucking. At least I do. iOS is smooth, Androind is jank AF.

Do any of the existing OSes provide this? Sure, maybe take an existing OS an modify it, assuming you can.

You mean for the PlayStation? That is a FreeBSD fork, probably chosen over Linux because of the license.

Sony and Nintendo both forked off of either NetBSD or FreeBSD. Sony's cameras at least up until the A7S2 run Linux (there's jailbreaks for these), although I never found any kernel / bootloader dump like it would be required.

Android suffers from being Java at the core, with all the baggage that brings with it.

PS4/5 was BSD. Only Nintendo and Microsoft runs own corporate proprietary OS.

Sony forked FreeBSD, but Nintendo didn't. They have BSD license headers because of some BSD socket code they include.

Nintendo is an interesting example though. According to Wikipedia they actually use a proprietary microkernel, which, if I'm reading this right, I think they developed themselves. Looks like the only open source components they have is some networking code which is published under the BSD license.

https://en.m.wikipedia.org/wiki/Nintendo_Switch_system_softw...

Sony cameras all run Linux. Models with "PlayMemories Camera Apps" feature like A7M2 support runs Android userland on top. It's probably easier to count the cameras that don't(like old Olympus).

Yeah, the various docs and presentations given by reversers on the details of nintendos os really showcase a lot of good design choices. An impressive amount of work for just trying to enforce a harder IP moat around entertainment software.

ChromeOS, which is based on linux has both fast boot and zero jank.