[jonhohle]

Linux, the kernel, is free.

Haiku is written by volunteers (and before them BeOS challenged Microsoft due to exclusivity contracts required of OEMs).

TempleOS was written by a single person.

There are literally dozens of operating systems baked into all kinds of things that have small or volunteer dev teams. QNX, VxWorks, IOS (the Cisco one), the multitude of Unixes and BSDs, boutique/experimental ones like SkyOS or ReactOS.

Would anyone buy Playstation OS apart from a console? I don't know if there's a market for that (how is SteamOS going?). There might not be consumer demand, but a B2B offering could result in a sustained business.

Companies used to provide an OS to sell hardware. Linux mostly consolidated that market, but that doesn't mean there isn't room for more (macOS, remarkably, is still rocking 35 years later).

[harshitaneja]

Linux required scale. It being free doesn't negate the requirement for a large group of contributors and corporate donors. Haiku OS doesn't have many serious users or use cases even after 18 years of development. I really appreciate the work they do but it shows how incredibly tough it is to make an operating system for the masses. TempleOS is definitely not something anyone uses except to try out the weird OS they heard about. It won't even run on my hardware without virtualization. QNX made by blackberry, IOS as you stated Cisco for its own hardware, VxWorks by TPG Capital and also an RTOS so not consumer hardware. SkyOS not in development for more than 10 years and never popular and ReactOS is intended to be binary compatible with an existing popular OS so even though it won't be popular it would be leveraging existing ecosystem of apps and resources.

I don't know what point you are trying to raise with playstation OS.

MacOS is developed by a 2 trillion dollar enterprise.

The point is not that OS can't be built without scale but rather that for a consumer OS ecosystem of applications and other resources and hardware choices are concerns that are really tough to solve without scale and thus the market consolidated to only a few popular players.