This example uses the D3 library to render a hierarchical tree from a small dataset of movies, grouped by distributor and genre. It shows the distribution of films across these categories, with nodes connected by lines and labeled with category names. The visualization is built using `d3.rollup` to create a nested data structure, `d3.hierarchy` to process it, and `d3.tree` to compute the layout. Circles represent nodes, and leaf nodes display the count of movies.