This example presents an interactive world map using D3.js and TopoJSON. It displays country boundaries from the world-atlas 50m dataset, rendered as SVG paths using the `geoNaturalEarth1` projection and `geoPath`. The map supports zooming via the `zoom` function, which applies a transform to the grouped elements. Hovering over a country highlights it in red through CSS, and clicking the sphere logs an event to the console, while country names appear as tooltips from a TSV lookup file.