Subdivision surfaces also go by the names of MetaNurbs (lightwave), hypernurbs(cinema 4D), uberNurbs(electric Image). If I recall most subdivision srufaces use a polygon object to describe a NURBS object.

Pixels 3D Had an excellent implementation, and would let a polygonal object define any tipe of spline object.

Subdivision surfaces are great for organic modeling. Curved surfaces are interpolated from the polygon object, and everything is smooth and shiny.