This example shows OS market share as a pie chart, with each segment labeled by its percentage value and accompanied by a legend listing operating systems and their shares in millions. Data is loaded asynchronously from a CSV file using `d3.csv`. The chart is rendered with SVG paths generated by the `d3.pie` and `d3.arc` generators, with categorical colors assigned via `d3.scaleOrdinal`. Segment labels are positioned using `arcGenerator.centroid`, and values are formatted with `d3.format`.