Gapminder is currently owned by google and a free open source flash version of this system can be used through the google documents spreadsheet applications menu. This requires a google account and your data to be uploaded. The graph when created will only appear as an image if taken outside this google application however and will remain static. Help with Google Documents can be found here.
Data Visualization Software
Graphpad is a powerful, easy-to-use, feature-rich and standards-compliant open source graph component available for Java. Application areas include Process diagrams, workflow and BPM visualization, flowcharts, even traffic or water flow etc.
yEd - Java™ Graph Editor is a powerful graph editor that is written entirely in the Java programming language. It can be used to quickly and effectively generate drawings and to apply automatic layouts to a range of different diagrams and networks.
XML/SWF Charts is a simple, yet powerful tool to create attractive web charts and graphs from dynamic XML data. The XML source can be prepared manually, or generated dynamically using any scripting language (PHP, ASP, CFML, Perl, etc.). The official tutorial explains exactly how you can use XML/SWF for your personal projects.
JFreeChart is a free 100% Java chart library which creates charts such as bar charts, line charts, pie charts, time series charts, candlestick charts, high/low/open/close charts, wind plots, and meter charts.
JFreeChart is licensed under LGPL license and requires Java 2 platform (JDK Version 1.3 and higher).