JFreeChart

JFreeChart is a free 100% Java chart library that makes it easy for developers to display professional quality charts in their applications.

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.