This is ShineOS - an online "operating system" (or just a big joke brought to life)
ShineOS contains many applications (web applications), and there will be more!
Currently there are applications such as: emulator (real), eaglercraft (minecraft), terminal (js commands, etc.) and others
WARNING: DO NOT TRY TO DRINK 5-6 OR 7-8 LITERS OF OIL
Also in ShineOS there are 2 desktop environments - Blue Sky (Windows-like) and EnviX (MacOS-like)
Perhaps some part of the code is made by AI (idk)
And also perhaps ShineOS is somehow inspired by the North Korean RedStar OS (i'm not sure)