ReactOS shows off SMP support in open-source take on Windows

Huge step towards the project's goal of being a drop-in replacement for older Microsoft operating systems

ReactOS, the open-source project for creating a binary-compatible drop-in replacement for Windows, has crossed a crucial milestone with a first look at symmetric multiprocessing (SMP) support.

The developers are clear: this is a work in progress and not yet in the trunk, but persuading the operating system to run in SMP mode to the point where one can get to the familiar face of the Windows XP Task Manager is an impressive achievement.

Wow!! #ReactOS running in SMP reaching Desktop!! As a Bonus: using Windows XP Task Manager to show the processors load! #opensource #kernel #smp pic.twitter.com/rkZzohTA6S

— ReactOS (@reactos) March 13, 2022

SMP support was present in Windows NT. While the silicon required was a bit exotic back when ReactOS was in its infancy, hardware support is commonplace today. As such, software support in ReactOS has become ever more important (certainly when taking a glance at the project's forums).

Development on ReactOS has been painfully slow. The project started in 1998 (actually 1996, if one counts a brief dalliance with Windows 95), with the goal of recreating the Windows NT kernel, along with some basic drivers. The most recent release was December 2021's 0.4.14, replete with kernel fixes, shell updates, and some more work on the intriguing Xbox port. It remains in a resolutely alpha state.

We took a look at 0.4.13 in 2020 and found the experience delightfully retro. The same applies to 0.4.14 (once we got it running – it continued to take exception to Hyper-V on our Windows 10 system) which is unsurprising. As the readme says, it continues to focus on Windows Server 2003 compatibility but "is always keeping an eye toward compatibility with Windows Vista."

That said, as Microsoft has pushed ahead with killing off the likes of Windows 7 (even Windows 10 is not much longer for this world), the case for ReactOS as a compatible replacement for the company's older operating systems has strengthened. "ReactOS is a replacement for Windows users who want a Windows replacement that behaves just like Windows," according to the project.

Getting SMP support up and running is a hugely important step towards to that goal. ®