This example displays a zoomable world map where each country is filled with a color intensity based on its population estimate. The choropleth uses a linear scale transitioning from light to dark red, with hover effects changing the fill to purple. It builds the map using `d3.geoPath` with a `geoMercator` projection and TopoJSON data from world-atlas, while population and country names come from a TSV file. Zoom interactions are handled through d3’s `zoom` behavior, transforming SVG paths.