A D3.js map renders world countries as light-green SVG paths atop a blue sphere, using the Natural Earth projection. The code loads GeoJSON from the world-atlas TopoJSON source, converts it with the `feature` method, and draws each country with `geoPath`. The sphere outline is generated from a spherical geometry object, while CSS applies fill and stroke styling. This example demonstrates a minimal choropleth-free geographic visualization, relying on `json`, `geoNaturalEarth1`, and `topojson` to project and display the data.