HdF

HDF (Hierarchical Data Format) is a set of file formats and libraries designed for the storage and organization of large, complex, and heterogeneous scientific data. Developed initially by the National Center for Supercomputing Applications (NCSA) in the 1980s, HDF has evolved through several versions, the most widely used being HDF4 and HDF5. The format supports multidimensional arrays, images, tables, and metadata, enabling researchers to store data of varying types and dimensions within a single, self‑describing file.

Key features of HDF include a hierarchical structure resembling a file system, where groups act as directories and datasets as files, allowing intuitive organization of related data. Built‑in compression and chunking mechanisms improve storage efficiency and enable rapid access to subsets of data without reading the entire file. HDF also provides platform‑independent binary representation, ensuring that files created on one operating system can be read on others without conversion.

The HDF library offers APIs for multiple programming languages, such as C, C++, Fortran, Python (via h5py and PyTables), Java, and MATLAB, facilitating integration into diverse scientific workflows. HDF5, the latest version, is the default format for many high‑performance computing applications, remote sensing data, and large‑scale simulations. Its open‑source nature and extensive documentation have contributed to broad adoption across disciplines including climatology, astronomy, bioinformatics, and engineering.