Abstract: A system for generating secondary content for display, the secondary content being augmented reality content corresponding to primary content for display by a first display device, the system including a primary content characterisation unit operable to characterise the primary content, a secondary content generation unit operable to generate, in dependence upon the characterisation of the primary content, secondary content including one or more secondary content elements associated with the primary content, and a content positioning unit operable to position one or more secondary content elements with respect to one or more elements in a real environment, where the user of a second display device is able to view the secondary content elements overlaid upon a view of the real environment at the respective specified positions.

Abstract: A saw blade having a concavely curved sawing edge and two oppositely-directed sets of teeth. During reciprocation of the blade, a first set of the teeth may cut during a first stroke direction and the second set of teeth may cut during a second stroke direction.