RE: Ribs for tapered wings
Of course, any 2D or 3D drawing or modelling package can be used.
But for a simpler approach:
1. Draw one of the profiles on a sheet of paper.
2. Put on photo copier, and use whatever scaling factor is required to give you the next rib, e.g. 110%
3. Repeat with 120% etc.
4. Cut ribs according to templates.
Magne