To FOSS projects, leaked source code is highly toxic and infectious. The FOSS community's attitude on leaked source is similar to the corporate world's attitude towards GPL in the early 2000s, but unlike GPL, this is not just exaggerated FUD - the dangers of leaked, unauthorized or proprietary source code is real. Once leaked sources found its way to FOSS projects, the entire project may become illegal and face potential lawsuits (see the history of how BSD was almost killed by AT&T's lawyers). And once leaked sources found its way to your brain, it's not 100% safe [0] to work on FOSS anymore and the best option is banning yourself from participating similar projects, it's almost a memetic virus.

Projects on reverse-engineering and reimplementing proprietary technologies are the most vulnerable. A decade ago, ReactOS's development was suspended for years until the codebase has been reviewed.

[0] It's not illegal. If you can absolutely guarantee your work is not a derivative work based on the leaked source, but just a reimplementation, it's fine to proceed (the clean-room approach is not always needed, it simply offers the strongest legal guarantee). But for a big project with numerous contributors, the risk is high.

I'm not sure if they want to go this way https://en.wikipedia.org/wiki/ReactOS#Internal_audit https://wiki.winehq.org/Clean_Room_Guidelines

They can't look at it without running the risk of copyright infringement [1].

[1] https://en.wikipedia.org/wiki/ReactOS#Internal_audit

That would be really bad for these authors to download or look at leaked code. That's exactly how you get yourself in legal troubles.

That's why they have policies to not look at any leak, and even with this ReactOS and Wine already had their share of controversies in the past.

This is not the first time Windows code leaks. I also have a vague recollection of one of these projects actually having to rip out and rewrite a subsystem because it turned out to be too close to original Windows sources found in one of those previous leaks.

In short, this leak likely won’t affect any project that is seriously trying to reimplement substantial parts of Windows, if they care at all for US law.

It's radio active for those projects if some reason they tried using this info.

It will reduce the number of eligible contributors. If you have seen the windows source you are not allowed to contribute to wine. Unless someone uses this as an opportunity to document the interfaces and create a test suite and thereby allows a clean room implementation the source code isn't just useless. It actively ruins the wine project.

Regardless of what you do, I'd be extremely careful about looking at leaked commercial source code. While I think you could legally get away with writing code that was just inspired by something you've seen, I not sure I'd want the hassle of having to potentially defend myself if it came to a lawsuit.