Jenkins CI is the leading open source continuous integration server. It is written in Java and has a wealth of plugins to support the building and testing of virtually any project. Jenkins supports multiple Software Configuration Management tools such as Git, Subversion, and Mercurial. This book explores and explains the many extension points and customizations that Jenkins offers its users, and teaches you how to develop your own Jenkins extensions and plugins. First, you will learn how to adapt Jenkins and leverage its abilities to empower DevOps, Continuous Integration, Continuous Deployment, and Agile projects. Next, you will find out how to reduce the cost of modern software development, increase the quality of deliveries, and thereby reduce the time to market. We will also teach you how to create your own custom plugins using Extension points. Finally, we will show you how to combine everything you learned over the course of the book into one real-world scenario.