JFreeChart Demo is a demo of another product, JFreeChart, that is a free Java chart library for program developers. By using JFreeChart, the Java developers will be able to include professional quality charts in the applications they build. JFreeChart Demo just demonstrates the charts that are included in that .class file. You will be able to download it and see the complete source code for every chart type in this demo, through a dedicated tab, only when you purchase the JFreeChart Developer Guide from Object Refinery Limited´s website, a 750+ page PDF document written by David Gilbert, the original author and maintainer of JFreeChart. Even if you don´t buy the guide, JFreeChart Demo shows you the different chart types included in JFreeChart, grouped in types (Bar, Pie, Chart, Gantt, Lines, XY, Combined, Financial, Dial, Miscellaneous, etc.). In some charts, you can even modify some parameters and see what effect they have. The demo will also show you how much memory is used by any specific chart.