This pie chart displays the distribution of users across Android, iOS, and BlackBerry OS, with each slice labeled by its percentage share. The visualization uses D3 v6’s `pie`, `arc`, and `scaleOrdinal` APIs to generate the chart, while `csv` loads and aggregates the underlying data from a remote gist. Rendered as SVG, it also includes a legend and title, with slice labels positioned via `arcPath.centroid` and formatted using `d3.format`.