The NEXRAD tri-agencies (Department of Commerce, National Weather Service; the Department of Defense, Air Force Weather Agency; the Department of Transportation, Federal Aviation Administration) have established the NEXRAD Product Improvement (NPI) Program as a long-term activity to steadily improve WSR-88D science and technology. The Radar Product Generation subsystem has been replaced with open systems compliant software and hardware (ORPG), and many algorithms have been implemented or improved. A similar effort to replace the Radar Data Acquisition subsystem is nearing deployment (ORDA). These system upgrades enable the operational implementation of new scientific applications and signal processing techniques to improve the forecast and warning missions of the NEXRAD agencies. Further, the NPI program has begun a project to implement dual polarization, and is working to integrate weather data from several FAA radar systems. An additional NPI effort is focused on improving tools to improve the process of developing, testing, implementing and maintaining the software involved with application enhancements to the WSR-88D. This paper discusses NPI projects, describes recent science enhancements to the WSR-88D, and explores the expanding opportunities for development and implementation of new radar science and techniques intended for the WSR-88D.