OSGI is a short form Open Service Gateway Intiative. It's a specification consisting of a modular system and service platform for the dynamic deployment of modules. As per the specification, the application can be broken down into modules and deployed independently. When we think of developing an OSGI application, it means that we need to use the OSGI API available to develop the application. The second step would be to deploy it in the OSGI container. So, while developing applications in OSGI, we can break the application into modules and independently deploy them, and then uninstall; we can also have various versions of the application running in parallel. In this chapter, we shall see how Spring supports the OSGI bundled development and the deployment of its application. We shall first start with OSGI and then gradually move over to Springs's support.