VTD can run under

Darwin (MAC OS)
Linux
HP-UX 9, 10 and 11
SunOS
NB:   HP-UX and SunOS are not supported since 2012

	I. Dependencies.
        ----------------

1) Fortran 90 compiler. 
   Supported compilers:g fortran 4.3.0 or newer and
                        Intel Fortran under Linux compiler 9.1 through 10.1.20
                        HP-UX Fortran compiler 2.4 or newer
                        Sun f90 compiler.

   NB: Intel Fortran under Linux compilers 10.1.21 through 11.1.037 have 
       a critical bug that generates code that produce WRONG RESULTS. 
       According to Intel representatives, this bug was fixed in 11.1.038.
       Although it has not been confirmed that this bug will affect any routine 
       from the VTD library, it is strongly suggested not to use affected 
       version of Fortran for Linux compiler.

2) C compiler;

3) petools. ( http://astrogeo.org/petools )

4) ners. ( http://earthrotation.net/ners )

5) BLAS. (Basic Linear Algebra Software). It can be either a vendor supplied 
          library or ATLAS. ( http://math-atlas.sourceforge.net/ )
   Refer to petools installation guide for details.

6) cfitsio 3.30 or newer. 
   You may install VTD without cfitsio. Then path delay caused by
   source structure will not be computed. If you do not need
   this feature, specify --without-cfitio in configuration.

   How to install cfitsio:

   1) Take source code from http://heasarc.gsfc.nasa.gov/docs/software/fitsio/fitsio.html
   2) Take patch from http://astrogeo.org/pet_inc/cfitsio-3.26.patch
   3) Define 
        $DIST            -- directory where the package will be built
        $cfitsio_version -- cfitsio version number
        $cfitsio_prefix  -- directory where cfitsio will be installed

      cd $DIST
      tar -zxvf /tmp/cfitsio3370.tar.gz
      mv cfitsio fitsio-${cfitso_version}
      cd fitsio-${cfitsio_version}
      patch -Np0 -i /tmp/cfitsio-3.26.patch
      ./configure --prefix=${cfitsio_prefix}  \
                  --enable-reentrant \
                    CC=gcc \
                    FC=gfortran \
                    CFORTRANFLAGS="-fno-underscoring" \
                    CFLAGS="-DNoUnderscoreAppend -DGNU -m64"
      make
      make shared
      make install


7) spd_client ( http://astrogeo.org/spd )

   Take source code, untar

   cd $DIST
   tar -jxvf /tmp/spd_client-20151111.tar.bz2
   tar -jxvf spd_client-20151111_example.tar.bz2
   cd spd_client_20151111
   ./configure --prefix=${spd_prefix}  --with-petools=${petools_prefix}
   make
   make install
 

8) gmake

	II. Compile and link.
        ---------------------


./configure
gmake
gmake install

  By default binary files are put in $HOME/bin and data files needed for
vtd are put in $HOME/share . Option --prefix= changes it. If configure 
does not find petools library, you need to specify the name of the 
library with full path explicitly using option --with-petools. 
Distribution kit contains also data files needed for computation of
path delay. By default these files are installed in $HOME/share/vtd
You can override these default with option --data.

Example:

./configure --prefix=/opt --with-petools=/opt --data=/data/vtd
            --with-cfitsio=/opt --with-spd_client=/opt --with-ners=/opt

  Complete list of configure options can be printed by ./configure --help

  The package VTD can be compiled with or without support of cfitsio
library for reading files in FITS-format. If the library VTD is compiled
without cfitsio support, it will not be able to compute and apply 
contribution caused by source structure.


	III. Post installation.
        -----------------------


  If you intend to use vtd you should apply definitions of environment
variables listed in file vtd_vars which was put in ${prefix}/bin 
directory, where ${prefix} is the name of the root directory which you have 
specified with option --with-prefix, or $HOME if you did not use this option.
Under tcsh or csh execute a command:

source ${prefix}/bin/vtd_vars

  It is a good idea to include this line in you shell startup command file.

  Examine source code of examples in sub-directory example.

  If you upgrade VTD, please first run make uninstall from the 
distribution of the old installation, and then install new version.