Under this project, the Hierarchical Data Format(HDF) scientific data format, which has been developed by the National Center for Supercomputing Applications, will be extended to add the ability to use interfaces and libraries from another popular file format, netCDF. This should enhance use of HDF and associated scientific visualization tools in the atmospheric and aeronautic research communities, and position HDF as one of only a very few data formats which are used by all major data manipulation and visualization applications across all the scientific and engineering disciplines supported by the NSF.