This example presents a collapsible hierarchical tree visualization using D3.js v3, where each node is rendered as a colored rectangle with text and tooltip support. The tree layout (d3.layout.tree) organizes nodes by depth, with curved SVG paths (d3.svg.diagonal) representing links between parent and child nodes. Users can collapse or expand branches by clicking on nodes, which triggers animated transitions (transition.duration) to update the layout. The visualization reads hierarchical JSON data containing node properties like type, code, and version, and uses jQuery alongside D3 for DOM manipulation and zoom/pan interactions.