As discussed earlier in the paper, it can be reasonable to start the X server having the default visual be an overlay visual. This is the approach taken by Hewlett-Packard. This would mean common X clients automatically use the overlay planes for creating windows. The normal planes could then be used for complex, probably 3D applications with scenes that are difficult to regenerate. Interacting with basic X clients in the overlay planes would not disturb the complicated scene thus avoiding expensive redraws.