What UI system is the Unity editor built on?

What UI system is the Unity editor built on? I need to make a tool for use with Unity but not be integrated within Unity itself. Having it look and feel similar to Unity would be ideal.

It’s built with Unity OnGUI code. That’s why it’s so extensible.

–Eric

I meant Unity editor wrapper itself as ot runs on OSX (or Windows). I am presuming that it’s UI is built using a framework of some kind. But perhaps not…

Or are you saying that the implementation behind Unity OnGUI is drawing the entire editor and interfacing it with the OS? If so, then crap, my wishes won’t come true.

Obviously it would use the OS drawing routines underneath, but if you’re asking if it uses QT or something, then no, it uses its own GUI system.

–Eric