The NCAR Command Language (NCL) is a free interpreted language designed specifically for scientific data processing and visualization. NCL has robust file input and output. It can read and write netCDF-3, netCDF-4 classic (as of version 4.3.1), HDF4, binary, and ASCII data, and read HDF-EOS2, GRIB1 and GRIB2 (as of version 4.3.0). The graphics are world class and highly customizable.

As of version 5.0.0, NCL and NCAR Graphics are released as one package.

The software comes with a couple of useful command line tools:

• ncl_filedump - prints the contents of supported files (netCDF, HDF, GRIB1, GRIB2, HDF-EOS2, and CCM History Tape)
• ncl_convert2nc - converts one or more GRIB1, GRIB2, HDF and/or HDF-EOS files to netCDF formatted files.