Gui Builder For Tools..

Does anyone know of any GUI building software out there that can be adapted for building Renoise tool GUI’s?

Or would one have to be built from scratch? Could it be done as a Renoise tool?

I think it would be useful in terms of speeding up development of tools but also in enabling users of Renoise who aren’t programmers to think of ideas and comunicate them.
It would also start moving Renoise into Reaktor/Max territory if such a tool came built in.