This interactive choropleth map displays global income groups, with countries colored by category and a legend allowing selection of specific values. Clicking a country highlights it, fades all others, and dims the sphere, while clicking the legend filters the map to matching countries. The visualization uses d3.geoNaturalEarth1, d3.geoPath, and d3.zoom for the map, with d3.scaleOrdinal and d3.schemeSpectral for colors, loading TopoJSON world data and TSV metadata from the world-atlas package.