GEMPAK, the GEneral Meteorology PAcKage, is an analysis, display, and product generation package for meteorological data. It is used at National Centers for producing operational forecast and analysis products. GEMPAK consists of a large compilation of individual programs which provide data access, computation and display capabilities. These programs can be used both interactively as well as in automated or batch oriented processing. Graphical User Interfaces provide convenient access to interactive data manipulation. A comprehensive set of decoders enables integration of real-time and archive data, products, and bulletins.