Quoting from MacNN:
On November 23, the US Patent & Trademark Office published two of Apple’s patent applications which were both filed in July 2006 and respectfully titled ‘Virtualization of graphics resources.’ Apple’s patents relate generally to computer graphics, and more particularly to virtualizing resources for computer graphics.
…
Graphics resources are virtualized through an interface between graphics hardware and graphics clients. The interface allocates the graphics resources across multiple graphics clients, processes commands for access to the graphics resources from the graphics clients, and resolves conflicts for the graphics resources among the clients.In one aspect, the interface is a graphics kernel that assigns an identifier to a resource when allocated by a graphics client and the client uses the identifier instead of an address for the resource when requesting access to the resource.
Because the native command structure for the graphics hardware is unaffected by the virtualization, neither the applications nor the hardware require modification to operate in conjunction with the present invention. Furthermore, because the virtualized resources appear as unlimited resources to the graphics clients, the clients can be simplified since, for example, they are no longer required to de-fragment or compact their assigned resources…
Read the whole article at source.