This example shows a hierarchical tree of muscle cars organized by manufacturer, with Ford and Dodge as the top-level brands and individual models like Mustang, Torino, Charger, and Challenger as leaf nodes. The tree uses a D3 v3 layout with color-coded rectangular nodes (grey for the root, blue for manufacturers, red for models, orange for sub-models) and animated SVG rendering. The visualization supports zooming and panning through d3.behavior.zoom, and each node has a dropdown shadow and arrow markers. The data is loaded asynchronously from a JSON file that defines the tree structure.