Architects and the like already work with a really great tree editor called Grasshopper. Easy to see cross sections through your tree as you are arranging compo

Architects and the like already work with a really great tree editor called Grasshopper. Easy to see cross sections through your tree as you are arranging components and relationships L->R or T->B, so there is potential to have very clear hierarchies depending on the style of the user. Also, I've been impressed with a lot of the invention that has happened around Grasshopper's UX + UI. I've been really surprised to see the design community emerge with the best graph programming editor, as opposed to something much more developer focused. It is of course not general purpose because you have to have Rhino to use it, but it can be used for general purpose programming since you can create custom components with .NET, ignoring most of the pre-built ones that are focused on parameterized geometry.