This example visualizes operating system market share using a pie chart with external labels and a legend. It displays Windows, macOS, Linux, and ChromeOS with their respective percentages computed from the raw CSV data. The visualization uses `d3.pie()` to compute slice angles, `d3.arc()` for rendering paths, and `d3.scaleOrdinal` with `schemeCategory10` for colors. SVGs are drawn via `d3.select`, and slices include white strokes, while labels are positioned using trigonometric calculations based on mid-angles.