This interactive map of world countries allows the user to switch between an orthographic projection and a Mercator projection by clicking on individual nations. The visualization also supports dragging to rotate the orthographic view and zooming, all rendered as SVG paths. The code uses the `d3.geoPath` and `d3.geoOrthographic` APIs from the D3-geo-projection library, and it loads country boundaries from a TopoJSON file alongside a TSV file containing country names. Dynamic rotation and zoom are handled through the `d3.drag` and `d3.zoom` interactions.