The shapefile distributed in this zip file is derived from the binary
GSHHG dataset used by GMT, the Generic Mapping Tools (gmt.soest.hawaii.edu).
While GMT uses a tiled, netcdf-formatted version for faster shoreline access,
these shapefiles contain complete closed polygons instead - hence some are
very very large. 
It comprises polygons from:
- Continental land masses and ocean islands, except Antarctica;
- Antarctica based on ice front boundary.

Please also see LICENCE and COPYING_LESSERv3.