HDF5 Release 1.3.x
    			Under Development


INTRODUCTION

This document describes the differences between HDF5-1.2.0 and 
HDF5-1.3.x, and contains information on the platforms where HDF5-1.3.x
was tested (????? careful, under construction)
and known problems in HDF5-1.3.x. For more details check the
HISTORY file in the HDF5 source.

The HDF5 documentation can be found on the NCSA ftp server 
(ftp.ncsa.uiuc.edu) in the directory:

     /HDF/HDF5/docs/

For more information look at the HDF5 home page at:
   
    http://hdf.ncsa.uiuc.edu/HDF5/

If you have any questions or comments, please send them to:

    hdfhelp@ncsa.uiuc.edu


CONTENTS

- New features
- Bug fixes since HDF5-1.2.0 
- Platforms Tested
- Known Problems

New features
============
   * The Virtual File Layer, VFL, is added to replace the old file
     drivers.  It also provides an API for user defined file drivers.
   * New features added to snapshots.  Use 'snapshot help' to see a
     complete list of features.
   * Added Thread-Safe support.  Phase I implemented.

Bug fixes since HDF5-1.2.0
==========================

Library
-------
   * The function H5Pset_mpi is renamed as H5Pset_fapl_mpio.
   * Corrected a floating point number conversion error for the
     Cray J90 platform.  The error did not convert the value 0.0
     correctly.
   * Error was fixed which was not allowing dataset region references to have
     their regions retrieved correctly.
   * Corrected a bug that caused non-parallel file drivers to fail in
     the parallel version.
   * Added internal free-lists to reduce memory required by the library and
     H5garbage_collect API function
   * Fixed error in H5Giterate which was not updating the "index" parameter
     correctly.
   * Fixed error in hyperslab iteration which was not walking through the
     correct sequence of array elements if hyperslabs were staggered in a
     certain pattern
   * Fixed several other problems in hyperslab iteration code.
   * Fixed another H5Giterate bug which was causes groups with large numbers
     of objects in them to misbehave when the callback function returned
     non-zero values.
   * Changed return type of H5Aiterate and H5A_operator_t typedef to be
     herr_t, to align them with the dataset and group iterator functions.
   * Changed H5Screate_simple and H5Sset_extent_simple to not allow dimensions
     of size 0 with out the same dimension being unlimited.
   * QAK - 4/19/00 - Improved metadata hashing & caching algorithms to avoid
     many hash flushes and also remove some redundant I/O when moving metadata
     blocks in the file.

Configuration
-------------

   * The hdf5.h include file was fixed to allow the HDF5 Library to be compiled
     with other libraries/applications that use GNU autoconf. 
   * Configuration for parallel HDF5 was improved. Configure now attempts to
     link with libmpi.a and/or libmpio.a as the MPI libraries by default.
     It also uses "mpirun" to launch MPI tests by default.  It tests to
     link MPIO routines during the configuration stage, rather than failing
     later as before.  One can just do "./configure --enable-parallel"
     if the MPI library is in the system library.
   * Added support for pthread library and thread-safe option.
   * The libhdf5.settings file shows the correct machine byte-sex.

Tools
------
    * h5dump correctly displays compound datatypes.
    * Corrected an error in h5toh4 which did not convert the 32bits
      int from HDF5 to HDF4 corectly for the T3E platform.
    * h5dump correctly displays the committed copy of predefined types
      correctly.
    * Added an option, -V, to show the version information of h5dump.
    * Fixed a core dumping bug of h5toh4 when executed on platforms like 
      TFLOPS.
    * The test script for h5toh4 used to not able to detect the hdp
      dumper command was not valid.  It now detects and reports the
      failure of hdp execution.
    * Merged the tools with the 1.2.2 branch.  Required adding new macros, VERSION12
      and VERSION13, used in conditional compilation.  Updated the Windows project files
      for the tools.            
    * h5dump displays opaque and bitfield data correctly.

Documentation
-------------

    * User's Guide and Reference Manual were updated. 
      See doc/html/PSandPDF/index.html for more details. 

   
Platforms Tested:
================
 Note: Due to the nature of bug fixes, only static versions of the library and tools were tested.


  AIX 4.3.2 (IBM SP)            3.6.6
  Cray T3E 2.0.4.81             cc 6.3.0.1
                                mpt.1.3
  FreeBSD 3.3-STABLE            gcc 2.95.2
  HP-UX B.10.20                 HP C  HP92453-01 A.10.32
  IRIX 6.5                      MIPSpro cc 7.30
  IRIX64 6.5 (64 & n32)         MIPSpro cc 7.3.1m
                                mpt.1.3 (SGI MPI 3.2.0.0)

  Linux 2.2.10 SuSE             egcs-2.91.66               configured with
  (i686-pc-linux-gnu)                                      --disable-hsizet
                                mpich-1.2.0 egcs-2.91.66 19990314/Linux 

  OSF1 V4.0                     DEC-V5.2-040
  SunOS 5.6                     cc WorkShop Compilers 4.2  no optimization
  SunOS 5.7                     cc WorkShop Compilers 5.0
  TFLOPS 2.8                    cicc (pgcc Rel 3.0-5i)
                                mpich-1.1.2 with local changes
  Windows NT4.0 sp5             MSVC++ 6.0

Known Problems:
==============

o SunOS 5.6 with C WorkShop Compilers 4.2:  Hyperslab selections will 
  fail if library is compiled using optimization of any level.