Imagine trying to build a free software (as in freedom) version of Windows that can run Windows drivers and software; well, that is what ReactOS has been attempting for years. Now, it has just marked a new milestone by implementing its first NT6 system call, bringing Windows Vista (and newer) compatibility a bit closer.
The project posted on X explaining that the first NT6 call within the ReactOS kernel has just been implemented. This development also included implementing various NT6 processor functions.
The system call that has been added is NtGetCurrentProcessorNumberEx, which is used for returning the processor number of the logical processor that a caller is running on. It’s unclear how long it will take ReactOS to become compatible with Windows Vista software, but it took Microsoft around half a decade to develop Vista after the release of XP and marked a major upgrade, even if it didn’t land well with users at the time.
Our first NT6 system call is featured on @phoronix!
— ReactOS (@reactos) July 3, 2026
While a mere NT6 call will do nothing for now, it is a remarkable moment of transitioning #ReactOS to Vista+ compatibility. https://t.co/1SLg4oTdZm
The newly added system call is not that exciting, but work has to start somewhere. In a subsequent post to X, the ReactOS team admitted that the system call will not do anything for now, but called it a remarkable moment in the transition to supporting Vista and later.
Have you tried ReactOS? Let us know in the comments what you think of the project. If it matures enough (it is still alpha software), would you consider replacing Windows with it?
Via: Phoronix