This line chart shows the cumulative number of unique logged-in VizHub users over time, from the platform’s launch in August 2018 to March 2022. The visualization highlights key growth events, such as a Medium post, the VizHub 2.0 Kickstarter, and the Datavis 2020 course launch, using annotation labels. The chart is built with D3 v4, using `d3.scaleTime`, `d3.scaleLinear`, `d3.line`, and `d3.axisBottom` and `d3.axisLeft` to render an SVG. Data comes from a local `users.csv` file, and gridlines are drawn via axis tick sizes.