Subject: ANNOUNCE: HDF5 beta release

From: Robb Matzke <[email-masked]>
Date: 16 Sep 1998 14:19:07 -0400

HDF5 is a new, experimental version of the Hierarchical Data Format (HDF)
that is designed to address some of the limitations of the current version,
HDF4, and to address current and anticipated requirements of modern systems
and applications.  The beta version of HDF5 is freely available in source
format from ftp://hdf.ncsa.uiuc.edu/pub/DIST/HDF5/ and a web site is under
construction at http://hdf.ncsa.uiuc.edu/HDF5/.

We urge you to look at this new version of HDF and give us feedback on what
you like or do not like about it, and what features you would like to see
added to it.

Why HDF5? The development of HDF5 is motivated by a number of limitations
in the current HDF format, as well as limitations in the library. Some of
the improvements upon HDF4 are:

* A file can have a 64-bit address space and be a single file or a
  collection of smaller files (HDF4 files were limited to 2GB).

* Dataset sizes are 64-bit quantities and the number of datasets per file
  is limited only by the file size (HDF4 allowed at most 20,000 complex
  objects in a 2GB file).

* HDF5 has a simpler, more comprehensive data model that includes only a
  few basic classes: datasets, spaces, types, groups, and files (the HDF4
  data model had inconsistencies and more classes than necessary).

* HDF5 was designed with an object oriented philosophy and the source size
  is approx. 1/3 of HDF4 but includes all the major functionality of HDF4.

* HDF5 supports parallel I/O effectively using MPI-IO.

The beta release includes most of the basic functionality that is planned
for the first release of the HDF5 library. However, the library does not
implement all of the features detailed in the format and API
specifications. Here is a listing of some of the limitations of the current
release:

* Some functions for manipulating data spaces have not been implemented.

* Some data types such as variable length types, pointers, and times are
  not yet implemented.

* Deletion (unlinking) and renaming objects is not yet implemented.

* The library is not currently thread aware although we have planned for
  that possibility and intend eventually to implement it.

-- 
Robb Matzke L-170                               #include <disclaimer.h>
Lawrence Livermore National Laboratory          Voice/Fax: +1 812 949 7318
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