Next-generation embedded systems in application domains such as multimedia, wired and wireless communications, and multipurpose portable devices, are increasingly turning to multiprocessor platforms as a vehicle for their realization. But entirely fixed platforms composed of entirely fixed components lack the flexibility and ability to be optimized to the application to offer the best solution in any of these areas. Configurability at multiple levels offers a much better chance to optimize the resulting multiprocessor platform. Existing and emerging technologies for configurable and extensible processors and the creation of configurable multiprocessor subsystem platforms offer significant capability to design teams to both differentiate and optimize their products.