This example displays a world map using a natural Earth projection with countries filled in light green and oceans in blue. It uses the D3 library’s geoPath and geoNaturalEarth1 projection to render the map, and TopoJSON’s feature function to convert geographic data from world-atlas TSV and JSON files. The interaction is a simple hover effect that turns countries red when the mouse passes over them, demonstrating a "cheap trick" for user feedback.