[EmilyHughes]

Going by how long ReactOS is developed and how unuseable it still is I wonder if the time would haven been better spent decompiling windows 2000 and structuring the code. Once that is done you have a solid base to modify and modernize the OS however you want.

[ACS_Solver]

No need to decompile Windows since there have been substantial code leaks, and more recently the entire (or near?) WinXP source leaked. It's even on GitHub.

The problem is of course that anyone using the source code would be in legal trouble, and ReactOS has a policy of not accepting contributions from anyone who has as much as looked at the actual Windows source. How well they maintain their clean room is an open question, but an OS based on leaked or decompiled code would definitely be getting sued into oblivion.