This package currently holds the programs mgd77convert, mgd77info, mgd77list, mgd77manage, mgd77path, mgd77sample, and mgd77track which can be used to extract information or data values from or plot marine geophysical data files in the ASCII MGD77 or netCDF MGD77+ formatsA.6). We expect this package eventually to replace the mgg package. The package is maintained by Paul Wessel.