First of all, let me say what a wonderful peice of software this is- trully a joy to use. I've been a long-time Rhino user and have recently moved to poly modelling via Softimage and Silo. It's hard to find a hybrid modeller and have actually started to code my own so I know how it is to work with curves and surfaces from a developer's perspective. The real problem is not the math behind the scenes but the interaction model/interface so I have to commend you on finding the right balance.

I do have a few questions regarding any future feature-set:

1. Any planned support for adding creases to curves and surfaces (i.e., tension, bias, continuity, and tangency)?
2. How about the ability to draw curves on surfaces (i.e. object snap to surface)?
3. How about the ability to extract icocurves from surfaces?
4. How about the ability to refine curves and surfaces?