As this book is focused on OSGi and Felix, it is important to keep a clear separation between materials that are OSGi-specific and those that are Felix-specific. Recognizing and following the OSGi-specific directives allows you to develop bundles for any framework that is OSGi-compliant.

For example, in Chapter 1, Quick Intro to Felix and OSGi, we've looked at the OSGi core specifications which govern the way an OSGi framework must behave and the rules required to be followed by the bundles targeted for an OSGi framework.

Felix is an OSGi-compliant service platform implementation. It also provides a selection of bundles that are OSGi-compliant. The sections having to do with installing and operating Felix are Felix-specific. However, there are chapters that will discuss bundles provided by Felix, but that may be used on any other OSGi compliant framework.

For example, the chapters talking about the Log Service and Http Service implementations will cover bits from OSGi specification as well as ones specific to the Felix implementation. Understanding which sides are part of the OSGi specification and which parts are Felix-specific will help when you want to replace the implementation bundle from one provider to another.

Furthermore, additional hints and discussions around general design-related topics and tools that help with the development activities apply to a context wider than that on which this book focuses. They aim to augment the basic integration requirements with ones that may improve the development experience.