CAD software, Computer Aided (Assisted) Design (Drawing)
Rhino is what's referred to as a Nurbs Modeller.
Non-uniform rational basis spline (NURBS) is a mathematical model commonly used in computer graphics for generating and representing curves and surfaces which offers great flexibility and precision for handling both analytic (shapes defined by common mathematical formulas) and freeform shapes.
There are other types, but we wont go into that.
Hey vortex, what did you use to render it? And can we see the unrendered model?