HDF
From Just Solve the File Format Problem
Summary
The Hierarchical Data Format (HDF) is a file format and associated APIs designed by the US NCSA for multi-dimensional datasets. Currently it has two main versions, HDF4 and HDF5, which are quite different in design, implementation, and API. Currently both are supported by the HDF Group, but HDF5 is generally considered to be technically superior. Another widely-used data format, NetCDF-4, is based on HDF5.