The interactive charts you see on Our World In Data are created using our own internal visualization app, OWID-Grapher. My colleague Aibek and I are always working to improve this tool—here is a summary of some of the recent feature additions.
In scatterplots where the timeline bar appears underneath, it is now possible to compare different points in time. Try pressing play on this chart to see a progression from the top left to lower right, representing the global development of both education and safer childhoods. You can hover over the lines to get more detailed information, or drag the endpoints of the timeline slider to compare different years.
Something to note about the grapher in general is that it is always possible to share an interactive chart as it currently appears. For example, if you set the timeline to show a particular year or range of years and then use the buttons in the lower right to link to or download the chart, the output will appear accordingly.
It is now possible to toggle the selection of one or more countries in a scatterplot by clicking on them. This allows for charts that emphasize outliers or other places of interest. For example, this chart shows the surprising divergence of the United States from other developed countries in healthcare expenditure and health outcomes. Try selecting another country and pressing the play button to see how the two countries have changed relative to one another.
The new legend on the right of these charts can be hovered over to view particular regions, or clicked to select them. This chart emphasizes that it is people in African countries who suffer most from the debilitating effects of communicable diseases.
Since the grapher generates these charts on the fly, if you're reading this post later on they may appear quite different to how they did at the time of writing. This is one of the advantages of having a big visualization database—it means that as we improve the code, the changes will apply retroactively to any charts authored in the past, keeping them up to date and consistent.
As they are now, there are several areas where I think these scatterplots could still be improved. The interactive selection of countries is not always intuitive, and lacks an effective mobile design. The legend could synchronize itself with the "graying out" behavior. And the timeline year transition speed is sometimes slower than it should be. Aspects to work on in the coming days!