This example displays a three-level hierarchical tree of programming languages, grouped by paradigm (Object-Oriented, Functional, Scripting). The SVG visualization uses color-coded nodes—orange for the root, blue for paradigm categories, and green for individual languages—with horizontal links. The code builds the hierarchy using `d3.hierarchy()` and applies a tree layout, drawing connections with `d3.linkHorizontal()` and labeling nodes via appended SVG text elements. The data is a static JSON object embedded in the script, with all elements rendered directly into an SVG canvas.