Hi,
I was looking at Tspline and they look really interersting. The way you modifiy your shape on the fly is great.
I was wondering how you could achieve the same result in Moi or something similar.
At the moment from what I watch the best way to modify your shape is to use the lofting technique presented by Samardac.
I found this technique cool but it need a big amount of work, you really have to plane your curves correctly.

One thing I was thinking that could help to modify your shape on the fly is being able to change a shape done with revolve rail.
But if you move one outline curve you have to tweak it to make it work with your rails curves.

So I was thinking, could you have a tool similar to slide edge in polymodeling where you take a curve and your railing curves and then move the curve you want to modify and it will follow the railing curve adjusting on the fly.
That could speed the process of having to rescale and reshape your curves and having something more interactive :D