The stated ambition of this book is to cover the many facets of distributed data management on the Web. I believe the authors have actually achieved more. They study the most precious asset of our age: data. The book is structured into three parts: “Modeling Web Data,” “Web Data Semantics and Integration,” and “Building Web Scale Applications.” This structure logically reflects three conceptual layers: syntax, semantics, and pragmatics.

In the first part, Extensible Markup Language (XML) is explained in sufficient depth, giving the reader insight into this standard for data management. The authors stress the management connection not only here, but actually quite often, starting with the title. Undoubtedly, “management” is a very popular word nowadays that has been brought into many different contexts, and the notion of Web data management is frequently used in recent research literature. The authors’ use is appropriate when many use it in a similar way; however, I am not sure if it best explains the contents of the book. In a sense, the reader learns both more and, perhaps, less. The book studies the nature of Web data including models for its representation and algorithms for its processing, providing more in-depth technical and mathematical knowledge than can be found in typical literature on management. On the other hand, however, managing something also requires many nontechnical skills that are not covered here at a depth that would justify, in my view, including the word “management” in the title.

The second part is devoted to the semantic Web and its main concepts: semantic description, annotation, and ontology. Again, the book goes into enough depth for the reader to understand the concepts sufficiently and be able to use them for such tasks as building ontologies for query answering or for data integration.

The third part is motivated by the recognition of the huge scale of Web data. In particular, the authors concentrate on Web search. Identifying indexing at the core of search and of distributed data access in general, they study how to index huge collections of data in a distributed way.

One of the distinguishing features of the book is the systematic inclusion of practice-oriented chapters that nicely complement the theoretical information. This is especially important in view of the intended audience: master’s level or advanced undergraduate students. The book contains numerous examples and exercises at the end of each chapter. The practice-oriented chapters are a very interesting and innovative enhancement, forming the basis for labs and projects.

In my view, for a topic that is still so new and is the subject of so much active research, this is an excellent textbook that I recommend. It is written with undeniable expertise, and is a perfect balance between scientific rigor and practical examples.