TempleOS
Temple OS and its forks. 

Temple OS
https://templeos.org/
https://templeos.holyc.xyz/
https://github.com/cia-foundation/TempleOS
Shrine OS
https://github.com/minexew/Shrine

ZealOS
https://zealos.net/
https://github.com/Zeal-Operating-System/ZealOS

ZenithOS
https://github.com/genericx64/ZOS
https://github.com/genericx64/ZOS/network/members