Several review articles on sonar system technology have provided a detailed description of the mainstream sonar signal processing functions along with the associated implementation considerations. This chapter attempts to extend the scope of these articles by introducing an implementation effort of nonmainstream processing schemes in real-time sonar systems. It provides a historical overview of sonar systems and introduces the concept of the signal processor unit and its general capabilities. The chapter discusses the sonar problem and introduces the development of a realizable generic processing scheme that allows the implementation and testing of nonlinear processing techniques in a wide spectrum of real-time active and passive sonar systems. It presents a concept demonstration of both the sonar technology and advanced signal processing concepts that are proving invaluable in the reduction risk and in ensuing significant innovations occur during the formal development process.