More often than not, I hear that the mission-critical stuff in Linux is done by paid people, the folks that work from 9 to 5 with a fixed time/resource schedule. Is software in Linux all like that? Say for example, Linux (kernel), systemd, Xorg, all the desktop environments, LibreOffice, Mozilla, Chromium and such.

The reason why I'm asking is because I kind of feel like the premise behind Linux "free, libre, *philanthropic*" and such is kinda wrong. Especially the latter. Do the people in the mission-critical stuff really care about its stability any more than commercial software devs do? Sure the projects driven by personal needs that are published are philanthropic in their nature, I'm having some of those too. But those are all non-critical and maintained as such. The stuff that's behind the steering wheel however? I'm not sure...

In essence, is the mission-critical part of the Linux ecosystem - however open-source it is - any different from other commercial software products QA-wise?

They've got a long enough hierarchy of code reviews and thus would also expect good enough testing

Also, do not mix up the linux kernel, the gnu tooling and separate programs and environments.

They often have wildly different structure for how they are developed.

The kernel, which is the actual linux part of this, is built and maintained by a huge number of people from many companies that are depending on linux for their existence.

But final review and approval are done by Linus Torwalds and a couple of other maintainers.

Other projects have different structure and could be more or less backed by companies.

So to discuss stability for the whole eco system is probably impossible.

But the open part means that the more central and important parts get more eyes on them and stability bugs that do affect users will get someone to loo at them.

The more niche the project is, or tied to a company, like a driver for a peripheral the more like normal corporate development it will be.

The only really true part of open source is that IF you are completely dependent on some part and the original developer or company stops maintaining it you do have the option to do it your self, if you have the know how.

And popular tools and items will usually have a more mixed group of maintainers and should there fore be more stable.

Not all devs that get paid are careless.
Not all devs that no not get paid care either.

Imagine being paid to code on that project that you worked for free before, would you care?

That and the community doing the reviews and testing is what makes opensource better than closed source.