NetCDF (network Common Data Form) is a set of software libraries and machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data.

The release of netCDF-4.0 in 2008 introduced a new, enhanced data model, and a new binary format based on the HDF5 data format and library, while maintaining complete backward compatibility for netCDF software and data files. We advise users and detail the choices they face with the new release. We describe some of the ways in which users are using netCDF. Some simple benchmarks are developed and the results presented. We also discuss future plans for the netCDF libraries.