This pie chart visualizes programming language usage by developers, with each slice sized by its percentage of the total. The chart uses D3 v5's `pie` and `arc` generators to create SVG paths, with `scaleOrdinal` assigning colors from a predefined array. Percentage labels are positioned using `arcGenerator.centroid`, and a legend displays language names and values. Data is loaded asynchronously via `d3.csv` from a GitHub gist, and the `format` function formats percentage values.