NURBS surface continuity technique?

 From:  shokan
1316.1 is selling a CD that has examples of using NURBS tubes squished into sculpted shapes, such as figures, a head, etc.. Nice stuff. The name of the CD is Nurbana... a term for a technique or technology I've read about before at a Blender site. It was sketchy though. Can anyone tell me how the examples were done on the CD and where I can find a tutorial maybe? Here's the CD site: