Over 20 years after Microsoft first added product activation to Windows, hackers have fully cracked the activation algorithm from Windows XP. This means that anyone can activate the system, even while offline, and despite the retirement of Microsoft’s Windows XP activation servers. And that any key generated for a particular PC will always work for that PC.

As it turns out, this crack first appeared last year, but a post to tinyapps.org that was further amplified by The Register, Ars Technica, and other online publications provides a timeline for various XP activation workarounds and circumventions, including for this latest—and likely last—hack. As the post notes, “game over.”

That said, it’s unclear what the use case is here, as mainstream (non-embedded) versions of Windows XP exited support in April 2014, well past its planned 10-year support lifecycle. And while XP was the most popular version of Windows by user base at the time, it was later eclipsed by Windows 7 and Windows 10.

And to be clear, using Windows XP on the Internet today is in no way safe. But for the nostalgic few—and the fewer still, like me, who write books about this topic—being able to run Windows XP free and clear, preferably in a virtual machine with no online connection—can be interesting, educational, and useful. And as we see with such out-of-date platforms as Amiga, OS/2, and others, there will always be a small enthusiast community out there. Ultimately, this one is for that audience.