The Draken's double delta design was truly revolutionary when the type first flew in October 1955. Saab says 612 were built for service with the Austrian, Danish, Finnish and Swedish air forces.
I also saw the Draken fly at Linkoping during Saab's 70th anniversary air show, along with several of the manufacturer's other historic types. Pictures here: http://www.flightglobal.com/AirSpace/photos/saab/default.aspx