[kirha]

From FAQ:

Why don’t you help ReactOS? ExectOS goals are very different from ReactOS, and contrast the project’s core philosophy as being quite on different paths. While ReactOS aims to replicate Windows® NT™, ExectOS is a completely new Operating System implementing the XT architecture which derives from NT™. Although both projects share the goal of being NT™ compatible, they intend to achieve it in different ways. What ReactOS tries to replicate, ExectOS only implements as a compatibility layer. Thanks to that, ExectOS does not need to strictly follow NT™ architecture and is capable of providing modern features.

Do you intend to cooperate with ReactOS to achieve common goals? No. We share Wine’s opinion on the inappropriate reverse-engineering methods used in the ReactOS project, as well as its association with the TinyKrnl project, which used every possible method of achieving the end result of having a 100% compatible results. This especially applies to the so-called ‘dirty’ way.

[malermeister]

Can you share a bit more about the inappropriate and dirty reverse-engineering by ReactOS and what the deal with TinyKrnl is?

This response really only answers the question for a select few people familiar with the windows reverse engineering community drama.

[kirha]

I don't know but similar can be found on https://wiki.winehq.org/Clean_Room_Guidelines

"Don't look at ReactOS code either (not even header files). A lot of it was reverse-engineered using methods that are not appropriate for Wine, and it's therefore not a usable source of information for us. [1]"

[forgotpwd16]

That looks strange and requires more information. ReactOS devs in past have submitted patches in Wine, since ReactOS itself uses some parts from Wine.

[kirha]

ReactOS takes from Wine, but Wine does not want to take from ReactOS any longer.

[temac]

Not surprising when you compare some leaked NT code and some ReactOS code. I'm not even saying they straight copied the source btw, but some consider that disassembling as a reference is fine (and using MS symbols...). Well it might even be legal in some cases (more cases that some licence-aware people commonly imagine), but this is a really risky stance to take. For sure ReactOS is very far from clean-room.

[kirha]

I think there are more reasons. Maybe let's move this discussion here https://news.ycombinator.com/item?id=40730327 I don't want to make this thread shit-post.