A bar chart displays the popularity of programming languages from Stack Overflow's 2019 survey, with values as percentages. Built with D3.js v5, the SVG visualization renders horizontal axes and animated bars, and includes hover interactions that highlight a selected bar, display a dashed reference line, and compute value divergences against other languages. The chart uses `d3.scaleLinear` and `d3.scaleBand` for axis scaling, `d3.axisLeft` and `d3.axisBottom` for ticks, and `d3.selectAll` with transitions to manage mouseenter and mouseleave effects.