Hi Christopher,

> how does flow differ from flow along surface in rhino

It's equivalent to the "Flow" and "FlowAlongSrf" commands in Rhino.

The main differences are that in MoI instead of having a separate command for flowing between curves or flowing between surfaces there is just one command that just pays attention to whether you pick a curve or a surface as the initial base object.

Also one other difference is that in the next v3 beta there will be a new "projective" option that will apply the object in a different way - I don't think that Rhino's flow has an exact equivalent of that.

See here for some examples of the new projective option which will be coming to Flow in the next MoI v3 beta:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4471.15

- Michael