I ended up doing a web search. Found this comment. “”” Godot's editor is built with Godot's own Control nodes which you can use for your games. In short, there'

I ended up doing a web search. Found this comment. “”” Godot's editor is built with Godot's own Control nodes which you can use for your games. In short, there's no external toolkit, Godot's editor is a Godot game. “”” And from looking at a tutorial it appears to be a retained mode UI.