[windsurfer]

This often-repeated statement doesn't really communicate how the editor works. While it does use many of the same APIs, you couldn't build the editor from within the editor (bootstrapping). The editor itself is largely written in C++ and not Godot's integrated language GDScript, you can see for yourself https://github.com/godotengine/godot/tree/master/editor

[chii]

i suppose the idea isn't that you can bootstrap the editor within the editor, but more like how unreal editor uses the unreal engine to render itself.