The software libraries used at NOAA to read and write data files for WMO formats GRIB and BUFR have been under continuous development for at least the last 30 years.These libraries play a vital role in many operational systems at NOAA, and are also used by teams and scientists outside NOAA. In this paper we describe the libraries and their capabilities, and document recent modernization efforts. We trust that these libraries will continue to provide value to NOAA and the science community for decades to come.