This example presents a world map colored to display sample population data for a selection of countries, with a grayscale fill for regions without data. It loads country boundaries as TopoJSON from the world-atlas package and uses d3.geoNaturalEarth1 for projection, d3.geoPath for rendering, and a sequential color scale with d3.interpolateBlues to encode values. Interactive mouseover events highlight countries in orange, while the map is rendered as SVG with a bold title.