Sure, but without it, you stand no chance at all.

windows is source-available if you have deep enough pockets: https://www.microsoft.com/en-us/sharedsource/enterprise-sour...

Does Microsoft also provide you the tools to build it? I assume there are many Microsoft internal tools, libraries, etc required to compile anything of note. Presumably it has been dog fooded for so long it would be impossible to bootstrap without some number of binary artifacts in hand.

Anyway, I was responding to someone who wouldn't run either on a spaceship so I still would like to know what they would want to run. I am from a formal verification school of thought, so I would want something sel4.

I'd want manual backup pushbuttons.

And another box close enough so the CD tray can press them when it opens.

No, but you can review the source code before (or at any point), whereas with Windows, you cannot even do that.

windows is source-available if you have deep enough pockets: https://www.microsoft.com/en-us/sharedsource/enterprise-sour...

I have not heard of anyone building their own, custom Windows though, how common is it? I do not see Windows forks around either (I get it, it would not be legal).

What do you think some OEMs do with Windows on their custom deployment devices?

This happens less nowadays, because stuff like Android and ChromeOS, so why pay Microsoft when free beer OSes exist.

For something like the spacecraft in the article, you absolutely would have the ability to get access to the Windows source code.

I've occasionally worked on drivers for windows and linux. In either case, I didn't really need to read the source code; neither was it a valuable proposition. If the advertised API didn't do what it was supposed to, I likely wouldn't have understood enough to fix it: and this is my point.

Just because you can read it, doesn't mean you can or will be able to actually fix it; not because of technicality, but because of personal knowledge.

In this case, they are both black boxes.

I mean, I agree, I am just saying that it is better (in general) to have the source than not having it.

How so?

I once spent three days trying to figure out an issue, stepping line by line through hadoop (after figuring out the issue was in hadoop and not my own code). Yay, I proved the issue was actually in Java itself. Guess what happened next? We avoided the bug. Why?

- We couldn't update Java.

- We couldn't change hadoop because we were using a packaged solution. So, we just filed a bug with them.

Had the source not been available, we would have just skipped all of that, and it would have been our vendor's problem 3 days earlier.