An OS by Scratchers, for Scratchers.
Back in mid- to late-2019, Scratcher elinero created a forum thread on the Scratch Collaboration Forums, looking to recruit members for a project inspired by OSWars called CollabOS, where people would sign up to add new features to an OS emulator on Scratch. Membership was relatively low, but soon rose very quickly, with 14 collaborators within the project's official development studio, ranging from mlcreater to Prokube and wamu_m. Many more had contributed to the project, but have since left.
Using some extremely complex coding, several active contributors are currently making cloud systems and encrypted chatrooms, things that break the boundaries of what was meant to be an introductory coding language for primary school children.
This is the github page for the CollabOS project on scratch. Check out the studio at https://scratch.mit.edu/studios/25917371/projects/ and the forum at https://scratch.mit.edu/discuss/topic/389988/