[kabdib]

Windows sources have escaped before. I doubt that Windows is buildable outside of Microsoft (and the bits are definitely not signable, since you need access to a key vault for that).

Useful for research, and finding security issues. Not much else.

[KekDemaga]

Might be helpful to the reactos and wine folks if unofficially.

[supergreg]

Actually the opposite. They can't work in the project of they've seen the actual MS code even if they write their own code.

[moonman272]

Ah well, if there's a rule...

[Buge]

Why is that?

You can break patents without ever knowing the patent existed. So looking at this code wouldn't trigger a new patent problem.

And simply looking at some code, closing it, then later writing code that does the same functionality is not breaking copyright. So looking at this code would not trigger copyright.

[ccrush]

Clean room reverse engineering. The idea that, if you build something with a specified interface (Windows API in this case) without prior knowledge of the implementation details, and you haven't broken any patents in doing so, then you haven't broken copyright either and you are free to do business. This is a gross oversimplification. See Intel vs AMD case for more details.

[yoklov]

Clean room is a defense against copyright and not patent, AIUI. For patents it doesn't matter if you knew someone had patented it.

Not a lawyer, though, but a quick search confirms this.