Linkedxform is a small and useful tool to rigging. In Max its very simple and I have two succession from Maya cluster deformer to make it more useful:
1- New button for create a dummy to controlling selected sub-object like Maya cluster.
2- Ability to control FFDs control points like cluster and lattice relationship in Maya.
A small Maya tutorial for cluster and lattice:
https://www.youtube.com/watch?v=yULnA1Imdso
