JFreeChart is a free 100% Java chart library that makes it easy for developers to display professional quality charts in their applications.The JFreeChart project was founded seven years ago, in February 2000, by David Gilbert. Today, JFreeChart is used by approximately 40,000 to 50,000 developers. JFreeChart’s extensive feature set includes:

• a consistent and well-documented API, supporting a wide range of chart types.
• a flexible design that is easy to extend, and targets both server-side and client-side applications.
• support for many output types, including Swing components, image files (including PNG and JPEG), and vector graphics file formats (including PDF, EPS and SVG).
• JFreeChart is “open source” or, more specifically, free software. It is distributed under the terms of the GNU Lesser General Public Licence (LGPL), which permits use in proprietary applications.

Requirements: Java 2 platform (JDK version 1.3 or later)
Demo: http://www.jfree.org/jfreechart/samples.html
License: LGPL License