What is OSGi? Simply put, OSGi is a standardized technology that allows developers to create the highly modular Java applications that are required for enterprise development. OSGi lets you install, start, stop, update, or uninstall components without taking down your entire system. The interest in OSGibased applications has exploded since major vendors like Sun, Spring, Oracle, BEA, and IBM have gotten behind the standard. OSGi in Action is a comprehensive guide to OSGi with two primary goals. First, it provides a clear introduction to OSGi concepts with examples that are relevant both for architects and developers. Then, it explores numerous practical scenarios and techniques, answering questions like: How much of OSGi do you actually need? How do you embed OSGi inside other containers? What are the best practices for moving legacy systems to OSGi?