I can't say with certainty because I don't work for Gore, but I believe that WindStopper is just a name change for what used to be Activent (developed in conjunction with Patagonia, and used in wind shells) and DryLoft (used in insulated clothing).

I have a DryLoft sleeping bag cover by Moonstone (without a protective inner scrim) that has a membrane that looks exactly like that of my Patagonia Activent wind shirt.

You guys probably already know that WindStopper/DryLoft/Activent is basically Gore-Tex without the polyurethane layer and without the requirement for seam taping.