Someone recently pointed me to the UTK web site which was displaying several demographic graphs on a page. I found that the graphs were being generated by an application called Highcharts. I visited their site and was able to download their free app for creating these, interactive, web graphs. There is also an online version of the app.
The impressive functionality of the graphs on the web page is that the viewer can click on certain elements to turn them off or on. If you are viewing the graphic data for four cities, you can choose to turn one or more of the cities off/on and this regenerates the graph on the page.
“FREE FOR NON-COMMERCIAL
Do you want to use Highcharts for a personal website, a school site or a non-profit organisation? Then you don’t need the author’s permission, just go on and use Highcharts…”