HDF stands for Hierarchical Data Format. It is a library and multi-object
file format for the transfer of graphical and numerical data between
machines.  It is freely available.

Features of the HDF File Format:

 + It is versatile. HDF supports several different data models. Each
   data model defines a specific aggregate data type and provides an
   API for reading, writing, and organizing data and metadata of the
   corresponding type. Data models supported include multidimensional
   arrays, raster images, and tables.
 + It is self-describing, allowing an application to interpret the
   structure and contents of a file without any outside information.
 + It is flexible. With HDF, you can mix and match related objects
   together in one file and then access them as a group or as individual
   objects. Users can also create their own grouping structures using an
   HDF feature called vgroups.
 + It is extensible. It can easily accommodate new data models,
   regardless of whether they are added by the HDF development team or
   by HDF users.
 + It is portable. HDF files can be shared across most common platforms,
   including many workstations and high performance computers. An HDF
   file created on one computer can be read on a different system without
   modification.

• Yury A. Zotov

• libhdf
• libhdf-devel