Revision with unchanged content. Emerging network applications are shifting from routing and traffic management to those requiring inspection and modification of packet contents. Such appli­cations act on data streams, and the requirement to process every byte of a packet exceeds the already-substantial processing capabilities of high-speed networking equipment. Network processors are application-specific processors that are optimized to bridge the gap between the performance of ASIC and the programmability of general-purpose processors. Performance on traditional network applications is impressive, but we believe that these architectures are not well-suited for the emerging packet applications. Stream architectures are specifically designed to apply a consistent set of complex operations to each of a sequence of elements. Packet processing shares many of the same characteristics of media and image processing that motivate stream architectures: little global data reuse, abundant data parallelism, and high com­putational complexity. Therefore, stream architectures have been proposed as effi­cient and flexible platforms for network packet processing.