On his relatively new Terra ETL Blog, which I had not noticed before, Dean C. Mikkelsen has a nice post explaining the Robinson projection, the compromise projection created for aesthetic purposes by the late Arthur Robinson. (You may recall that from 1988 to 1998 the Robinson was the projection used by the National Geographic Society’s world maps, shoehorned between the previously used Van der Grinten and the currently used Winkel Tripel.) Via Planet Geospatial.