HDF5 is a library for storing large numerical data sets.
HDF stands for Hierarchical Data Format and was designed to save and retrieve data from/to large structured files.
It also supports parallel access to files in HDF5 format, particularly in the MPI environment. The HDF5 library can be used from C, C++ (with some limitations) and Fortran.
Files can optionally be saved in text, binary and compressed format (if zlib is available).