Operating System Mockups

Operating System Mockups (commonly referred as OS Mockups or OSM) is a cult dedicated for people who creates concepts of fake operating systems or fake versions out of already-existing operating systems (e.x. Linux, Windows, macOS, etc), along with sounds of startup and shutdowns. It's been a thing since 2008 with the boom of "Never Released Windows Versions" and nowadays it's still an alive cult and a community for it.

The first known video named as "OS Mockups" was created by Neptune98 in 2018, which is now reuploaded to The WNR/NROS Archive Bin.