JOpenChart is a free Java Toolkit and library for embedding charts into different kinds of applications, no matter if they are server side, desktop or web applications. Commercial solutions are pretty expensive and at the time I started working on JOpenChart, there was no satisfying open source solution available. Currently, the library provides all the functionality to draw different kinds of charts, like line, bar, pie and plot charts. Additionally, the class structure includes the necessary classes for the encapsulation of sets of data and the classes for all parts of a typical chart, like a coordinate system, coordinate axes, legends, title and chart renderers. I put great effort into a good design, ie understandable, logical class structures, elegant interfaces, use of abstract classes etc. The library is easily extendable to provide your own functionalities. This is best illustrated by noting, that all the Renderer classes, which paint the charts, have about 150 - 200 lines of code. That's pretty easy, isn't it?