As described by the authors, the goal of this book is the proposal of a mix of concepts, notations, and techniques for the construction of data-intensive Web applications, which can be used by Web development teams to support all the activities of the application lifecycle, from analysis to deployment and evolution.The authors achieve this purpose, and provide an easy to read, but more importantly, an easy to follow set of instructions, methods, and examples to guide programmers in moving to the data-intensive applications that the more dynamic Web and portal technologies require. The books combination and extension of known modeling techniques in a new constellation, to create a new software engineering technique, may well prove to be its major contribution. The creativity of the combination of techniques to form a method is remarkable, as is the books easy pedagogic style.A conceptual modeling language, Web Markup Language (WebML) is introduced in the text. This language follows the entity-relationship (E-R) model and Universal Markup Language (UML) syntax, and thus will be natural for those familiar with E-R and UML. This language is used to guide the reader in specifying and designing a Web application, including requirements specification, data design, and hypertext design. A data intensive Web application is a Web site that accesses and maintains large amounts of structured data. Most current Web sites and emerging application sites are of this nature.