Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Madeline is an open-source clone of Mathematica. It hopes to provide the same efficiency and robustness that are needed for high-end mathematics. Released under GNU GPL license. Open source describes practices in production and development that promote access to the end product''s source materials. Some consider open source a philosophy, others consider it a pragmatic methodology. Before the term open source became widely adopted, developers and producers used a variety of phrases to describe the concept; open source gained hold with the rise of the Internet, and the attendant need for massive retooling of the computing source code. Opening the source code enabled a self-enhancing diversity of production models, communication paths, and interactive communities.