This example demonstrates the Eckert III map projection, a pseudocylindrical projection that preserves equal area. The SVG canvas displays a graticule and world map, with landmasses rendered in dark gray and country boundaries in white. Using the D3 v3 library, the code employs `d3.geo.eckert3()` for the projection, `d3.geo.path()` to draw geographic paths, and `d3.geo.graticule()` to generate the grid. The world map data is loaded from a remote GeoJSON file via `d3.json()` and transformed using the TopoJSON library.