Next Generation Application Integration: From Simple Information to Web Services

This is an introductory chapter, thus not for readers who already have a working knowledge of middleware. Having said that, it's probably not a bad idea for those of you who need a refresher to run through the basics again, including messaging, RPCs, distributed objects, and transaction servers. If you have no need to review these concepts, this can be a jumping-off point for the next several chapters, which cover middleware concepts and technology.

It is important to understand these concepts as we move forward in the book. Many of the more advanced and stylish notions, including Web services, are based on existing middleware models. For example, those who already understand distributed objects will have no problem understanding Web services.

I have devoted the first part of the book to application integration approaches and implementation. In the following chapters, we will concentrate on the technology that makes application integration possible: middleware and standards. This chapter provides an overview of middleware, setting the stage for the following chapters to describe several types of middleware technologies that may assist us in solving the application integration problem.