Scene Tree

 From:  okapi
1944.12 
C4d would be interesting to look at in my opinion.
To me it has by far the best scene management concept.

It has a scene tree and a distinct layer manager. It may be worth looking into.

Also, a nice feature it has in the scene tree, is that it allows you to 'paint' layer information from one object to any other object near it in the scene tree.
Very quick way to change attributes (hard to describe).