This example shows an interactive collapsible tree visualization of the Flare dataset, where nodes can be clicked to expand or collapse their children. Built with D3 v6, it uses a hierarchical layout (`d3.tree`) and horizontal links drawn with `d3.linkHorizontal`. The SVG rendering includes smooth transitions between states, and the view supports zooming via `d3.zoom`. Node positions update with animated transitions, and the data is loaded from a JSON file using `d3.json`.