SailCut4.09 is an excellent sail design program by Robert Laine, linked to Carlson Design hardware. SailCut4 cross-cuts Marconi and gaff sails with simple and robust 3-d shape control (user manual). SailCut6.10 is for asymmetrical spinnakers, defining the flying sail in 3-d rather than just 2-d (user manual). Other programs allow spinnakers to fly away from their over-simplified 2-d outlines. SailCut8 is for junk rigs and batwing sails, and SailCut5is ready to cut windsurfer sails on your Carlson Design plotter/cutter.