This example presents a rotating world map built with D3.js and the d3-geo-projection library. The map displays country borders and graticules over a sphere, and users can drag to rotate the projection. Clicking on a country switches between orthographic and Mercator projections, with a special case for the United States. The visualization uses world-atlas data and employs `d3.geoPath`, `d3.geoGraticule`, and custom drag and zoom interactions.