Browser page as your desktop wallpaper – what more could you need!
This one is incredibly simple and simply uses a cool feature of windows, and to the best of my ability I’ll explain it from memory
So windows has a interface that I’ll call the window stack, they can be freeform and click and move them around, or locked inside a parent, in fact your desktop is itself one of these windows.
To render a GUI behind the desktop as a wallpaper, we simply need to create a program window, and then search for the window that contains the wallpaper and insert our program window as a child of that window. This is really trivial on windows, and doesn’t require any special access. It’s a straight recursive search of the window tree.