Since the release of jQuery in 2006, multitudes of plugins have been developed to provide solutions to a huge number of previously tricky problems. One of those tricky problems was the display of graphical data on a web page.
Flash was the only real solution, however as with anything written in Flash, it required a plug-in, there was no access to the source code, and the solution was usually heavyweight.
Now jQuery can take over the strain, and provide a lightweight solution to any website.
One particularly nice charting solution built with the jQuery library is called Highcharts. It is freely available for non-commercial use, and can be configured to produce bar, line, area, column and pie charts.
Website: http://www.highcharts.com