               README for HDF 4.1r2 Distribution
               ---------------------------------

Obtaining the latest version
----------------------------
 The most recent version of the distribution can be obtained from
 the NCSA ftp archive site at:

     ftp://ftp.ncsa.uiuc.edu/HDF/HDF_Current

Distribution Layout
-------------------
 There are five subdirectories in this directory:

   config -- contains machine dependent makefile fragments(mh-<os>). 

   hdf    -- contains the source code for the HDF 'base library', the 
             the multi_file annotation interface, the multi_file raster
             image interface, HDF command line utilities (hdp, the hdf 
             dumper is in mfhdf/), Pablo instrumentation support, 
             and a test suite. It also contains the software
             distributions for IJPEG(hdf/jpeg) and ZLIB(hdf/zlib) 
             which are required by the HDF library. 
             Please see the README in each directory for further info
             on each package. 

   mfhdf  -- contains the netCDF(mfhdf) part of the HDF/netCDF distribution
             and HDF dumper utility(hdp).

   java-hdf -- optional Java interface and Java HDF Viewer.  The Java
               products are built separately after the library has
               been built.  Change to the java-hdf directory and
               see the README.  
               See: http://hdf.ncsa.uiuc.edu/java-hdf-html/

   man    -- incomplete set of man page(s) for HDF.

   release_notes -- descriptions on new features and bug fixes in this
                    release. Files in this sub-directory can be used 
                    as supplemental documentation for HDF4.1. These files 
                    are also available on the NCSA ftp server, 
                    in /HDF/HDF_Current/release_notes.

Third Party Software Requirements:
---------------------------------
 1. IJPEG distribution release 6b(libjpeg.a). The "official" site 
    for this is ftp://ftp.uu.net/graphics/jpeg/jpegsrc.v6b.tar.gz


 2. ZLIB 1.0.4(libz.a) distribution.  

 Both of these distributions are included with this distribution
 in 'hdf/jpeg' and 'hdf/zlib'. The HDF/netCDF base distribution
 in known to work with these versions only.

System Requirements
-------------------
 To build the HDF library from source, you need:

   * an ANSI C compiler. The native ANSI compilers on the above 
     platforms are supported. On platforms where no ANSI compiler
     was available the free GNU ANSI compiler GCC was used.

   * a Fortran 77 (F90 for Crays) compiler if you want Fortran support.
     You can compile both libraries without Fortran support by setting 
     the Fortran compiler variable 'FC = NONE' in the respective
     makefile fragment(mh-<os>) found in the top-level 'config'
     directory. See the INSTALL file for further details on 
     configuration and installation.

Configuring/Testing/Installing 
------------------------------
 See the INSTALL file for instructions on configuring,
 testing and installing for Unix and non-UNIX systems.

DOCUMENTATION/FAQ/HELP
----------------------
 The HDF documentation can be found on the NCSA ftp server
 in the directory /HDF/Documentation.  The HDF home page is at:

      http://hdf.ncsa.uiuc.edu/

 An FAQ is available on our ftp server, as well as under
 "Information about HDF" in the home page.

 If you have any questions or comments, or would like to be
 added to or removed from our hdfnews email list, contact us
 at:

      hdfhelp@ncsa.uiuc.edu


