When Windows 10 was released, Microsoft announced that it would be the last numbered release of Windows. Six years from that and it looks like they silently backtracked from that decision.
About a week ago, a build of Windows 11 surfaced on some websites. Some say that the build was leaked by a Chinese company, Baidu, but I've seen no proof of that.
The build date of the system is May 2021, though it probably is an older build: the changes in it are too minor to justify a big release. For example, the Settings app remains unchanged between Windows 10 and its successor.
After getting a bit of traction, videos, tutorials and news articles about it literally exploded; my YouTube homepage contained only Windows 11 videos for a day.
But almost none of them shared a link. Except Enderman, tech youtuber who shared the first link and, together with other users, helped put together a website that acts as a collection of links.
If you want to try it out on a real system, be sure to skip the installer that checks for TPM2.0 compliance.