Rhino3D
General Purpose CAD 3D modeler. NURBS-based surfaces, SubD modelling.
Rhinoceros provides a vast array of tools to model any geometry, freely and accurately. Helps to materialize a concept into a fully-defined model, including 2D drafting, rendering, prototyping. Rhino3d handles curves, surfaces, and solids with no limits in complexity, but also meshes and point clouds.
With latest Rhino3D version 7, McNeel have introduced SubD geometry. SubD is a new geometry type that can create editable, highly accurate shapes. Unlike other geometry types, SubD combines free-form accuracy while still allowing quick editing.