The internet and the web have effected a profound and permanent change in our world and the way we view it. In both our professional and our social lives the consequences are with us every day as we try to evaluate, assimilate and utilize each new stage in the technological evolutionary process. Web 2.0 is the name used for convenience as a label for the present stage, in which the emphasis is increasingly on interactive communication and semantic enrichment. (Exactly what is meant by ‘Web 2.0’, and indeed whether such a concept as ‘Web 2.0’ really exists, is discussed in more detail in Chapter 2 ‘Web 2.0 in Healthcare Information: an overview’.) Web 2.0 applications are just beginning to reveal their potential as a way of improving and maintaining education and healthcare information in a wide range of situations, for caregivers and consumers alike.

Such is the pace of change, and such is the range of Web 2.0 tools and services on offer, that, while the journal literature provides an extensive coverage of recent developments, any attempt to produce a book surveying and summarizing the current state of affairs is inevitably destined to be overtaken by events. That certainty should not be seen as an argument against trying, though: the author or editor who waits for a more settled and stable state of affairs will in all probability be doomed to wait for ever. We share the belief of those others who have ventured into print in this area that there is a strong argument for providing the more considered, in-depth and reflective overview of web-based activities that a book makes possible; mapping key stages in the web's evolution, in the impact it has on our lives, and in the opportunities it enables us to grasp. Each book on the web is thus part of an incremental process of both advocacy and record. So, in formulating the case for this book we were – and remain – convinced that there is indeed a place for it and an audience that will benefit from reading it.

Let us first be clear as to what this book is not. It is not a manual designed to provide definitive and exhaustive instructions in how to develop or use Web 2.0 tools. The message throughout is suggestive rather than prescriptive.