One company that is well past the design stage is SkySails.
New York Times(Aug 27, 2012)
"By heavens! the little witch still holds her way with us!—Have the skysail set, and rig out the top-gallant-studd'n'sail!"
Various, The Portland Sketch Book(2012)
He was as steady as a bollard, And gallant as a skysail yard.
Masefield, John, Reynard the Fox(2011)