HDF version 4.3.1-1 currently under development

Full Documentation and Programming Resources for this release can be found at

https://portal.hdfgroup.org/hdf4/

See the RELEASE.txt file in the release_notes/ directory for information specific to the features and updates included in this release of the library.

Several more files are located within the release_notes/ directory with specific details for several common platforms and configurations.

INSTALL - Start Here. General instructions for compiling and installing the library
INSTALL_CMAKE  - instructions for building with CMake (Kitware.com)
INSTALL_WINDOWS and INSTALL_CYGWIN - MS Windows installations.

The following public forums are provided for public announcements and discussions of interest to the general HDF4 Community.

• Homepage of the Forum https://forum.hdfgroup.org

• News and Announcement https://forum.hdfgroup.org/c/news-and-announcements-from-the-hdf-group

• HDF4 Topics https://forum.hdfgroup.org/c/hdf4

These forums are provided as an open and public service for searching and reading. Posting requires completing a simple registration and allows one to join in the conversation. Please read the following instructions pertaining to the Forum's use and configuration https://forum.hdfgroup.org/t/quickstart-guide-welcome-to-the-new-hdf-forum

HDF4 does not release on a regular schedule. Instead, releases are driven by new features and bug fixes, though we try to have at least one release of each maintenance branch per year. Future HDF4 releases indicated on this schedule are tentative.

HDF 4.4.0 (February 2025)

• We will drop support for FORTRAN 77 and move to modern Fortran (2003 or 2008)
• HDF4 includes an ancient netCDF 2.3.2 API along with HDF4-built ncdump and ncgen tools. Support for these will be dropped in 4.4.0. netCDF APIs and tools should be obtained from Unidata.
• (maybe) libdf and libmfhdf will be merged into a single libhdf4 library, Fortran will be built as a separate library

The goal of the HDF 4.4.0 release is to address long-standing deficiencies and bring HDF4 in line with HDF5's build practices. This should allow HDF4 to work better with modern systems and compilers and be more easily maintained.

The 4.3 maintenance line will be retired when 4.4.0 releases. There are no more planned HDF 4.3.x releases.

Periodically development code snapshots are provided at the following URL:

https://github.com/HDFGroup/hdf4/releases/tag/snapshot

Source packages for current and previous releases are located at:

https://portal.hdfgroup.org/downloads/

Development code is available at our Github location:

https://github.com/HDFGroup/hdf4.git

The top level of the source code distribution contains the following subdirectories:

bin -- Scripts for maintenance.

config -- Configuration files to be used by configure script.

doc -- HDF 4.2 to 4.3 Migration Guide

hdf -- The source code for the HDF 'base library', the multi-file annotation interface, the multi-file raster image interface, HDF command line utilities, and a test suite. Please see the README in each directory for further information on each package.

java -- The Java HDF JNI library

m4 -- Autotools macros and libtool files for building with autotools.

mfhdf -- The netCDF(mfhdf) part of the HDF/mfhdf distribution and additional HDF utilities, such as hdp, hrepack, hdfimport, etc.

release_notes -- Installation instructions for UNIX and Windows. Descriptions of new features and bug fixes in this release. Files in this sub-directory can be used as supplemental documentation for HDF.

• JPEG distribution release 6b or later.

• ZLIB 1.1.4(libz.a) or later.

To build the HDF library from source, you need:

• C and Fortran compilers. For a list of the supported compilers, see release_docs/RELEASE.txt file.