Released versions of package FD
                                                                   
                                                     
    5.20 (1998, October):
            *** First release consisting of program and subroutines files
            'modfd.for','fdmod.for','fd2d.for','fdaux.for','gmtra.for',
            'newpar.for','newpar.pl','fdmax.pl', demo data, scripts and
            history files. ***
                                                     
    5.30 (1999, June):
            'fd2d.for', 'fdaux.for': Erroneous sign in output snapshots
              fixed.  Comments in 'fdaux.for' improved.
            'fdmod.for','newpar.for': Updated according to changes
              in 'fdaux.for'.
            'modfd.for': Updated according to changes in 'model.for'.
            'fdmax.pl: Updated according to changes in 'grdnorm.for'.
            'snap.cal': Confused div and rot corrected.
            'fd.h': Snapshots supplemented with the receivers.
            'modfdps.h': Colours of complex blocks changed.
            *** new ***
            'addrec.cal': Script for 'grdcal.for' to overlay snapshots
              with receiver positions.
                                                     
    5.40 (2000, May):
            'modfd.for': Problems with gridpoints at interfaces fixed.
            'fdaux.for': Erroneous averaging along the X1 axis fixed.
                                                     
    5.50 (2001, June):
            'fdmax.pl': Missing apostrophes at data filenames fixed.
            'fdsnaps.htm': Mistype in a comment line corrected.
                                                     
    5.51 (2008, June):
            Attribute TYPE="..." added into all HTML links
              to text/html or text/plain files with extension other
              than .htm (without date or version change).
                                                     
    5.52 (2009, June):
            E-mail addresses replaced by WWW addresses
              (without date or version change).