GWT Google Charts Tutorial
Google Java Module is a open source java based library to provides an elegant and feature rich Google Charts visualizations within a GWT application and can be used along with GWT widget libraries. There are chapters discussing all the basic components of Google Charts with suitable examples within a GWT application.

Google Charts is a pure JavaScript based charting library meant to enhance web applications by adding interactive charting capability. Google Charts provides a wide variety of charts. For example, line charts, spline charts, area charts, bar charts, pie charts and so on. This tutorial will teach you the basics of Google Charts.

Google Web Toolkit (GWT) is a development toolkit for building and optimizing complex browser-based applications. GWT is used by many products at Google, including Google AdWords and Orkut. GWT is an open source, completely free, and used by thousands of developers around the world. It is licensed under the Apache License version 2.0.