.hdf

Standardized file format for storing scientific data; used in environmental science, non-destructive testing, neutron scattering, and aerospace applications; HDF utilities can manipulate, view, analyze, visualize, and convert scientific data from HDF files.

Two commonly used versions of HDF include HDF4 and HDF5. Each version includes software libraries that contain functions for analyzing and manipulating the data in HDF files.

The HDF Group maintains a list of programs that can read and process HDF files. One common open source option is GDAL - The Geospatial Data Abstraction Library.