Hdf5

The Hierarchical Data Format (HDF) version 5 file format was designed for scientific data consisting of a hierarchy of datasets and attributes (or metadata). HDF is a product of the National Center for Supercomputing Applications (NCSA), which supplies the underlying C-language library;

IDL

IDL provides access to this library via a set of procedures and functions contained in a dynamically loadable module (DLM).

IDL>HELP, 'hdf5', /DLM