The back cover of Calhoun’s book Exploring Digital Libraries: Foundations, Practice, and Prospects declares it “a landmark text on digital libraries for students of LIS, educators and practicing information professionals throughout the world.” It also states that it provides “an authoritative and in-depth treatment of the digital library arena, from the field’s emergence to current topics and future prospects.” Calhoun is a prolific and well-respected author and lecturer on the subject of digital libraries, and is definitely someone worthy of earning such accolades.

The book consists of two main themes. The first is a broad, international overview of the past twenty-plus years of digital libraries, while the second concerns the social roles digital libraries play in relationship to their online communities. Chapter 1, “Emergence and Definitions of Digital Libraries,” covers the first decade of this brave new world. The World Wide Web had been born, costs associated with computing had become much more affordable, and the National Science Foundation assembled a series of workshops on how to make digital libraries a reality. Projects such as the eLib Programme in the UK and the Digital Library Initiatives (DLI-1 and DLI-2) in the US, plus Project Gutenberg and the Internet Archive, gave a taste of what was to come. Calhoun also uses this chapter to establish the definition of digital libraries upon which she bases the rest of the book. In her eyes, digital libraries are both a multidisciplinary field of research and practice, and the systems and services that support the advancement of knowledge and culture; contain managed collections of digital content; and often utilize architecture from the computer and information science/library field (e.g., repository, resource identifiers, user interface).

In chapter 2, “Outcomes of Digital Libraries’ First Decade,” Calhoun identifies several key results from this initial period. These include a new field of research and practice, the transformation of scholarly communication processes, open access, digitization and digital preservation, metadata and its standards, and actual working digital libraries and the communities they serve. Each outcome is discussed in detail, and introduces such topics as D-Lib Magazine, PageRank (Google’s forerunner), the Open Archives Initiative (OAI), JSTOR (short for Journal Storage), Dublin Core, the Library of Congress’ American Memory, and the British Library Online Newspaper Archive. Chapter 3, “Key Themes and Challenges in Digital Libraries,” introduces the concept map that Calhoun created based on the major themes from the digital library literature of the decade 2002–12. The map consists of a collection of keywords plotted in a continuum of themes and topics arranged from “collections” to “communities” (x-axis) and from “technology” to “social and economic aspects” (y-axis). The remainder of the book is based on both this map and the four challenges that she has identified to building collections and communities for digital libraries: interoperability (providing uniform access for users to diverse information from various systems), community engagement, intellectual property rights, and sustainability.

Chapter 4, “Digital Library Collections: Repositories,” begins with a look at traditional library collections and collection development in light of the web. It provides a close examination of digital repositories, including content usage and discovery (e.g., Google Scholar), the application of repository software (e.g., DSpace, Fedora), and web services such as XML (Extensible Markup Language), and concludes with examples of next-generation repositories such as Drupal and Scholar’s Workbench. Chapter 5, “Hybrid Libraries,” wraps up the book’s first theme by examining the interaction between library users and hybrid libraries (collections of non-digital, digitized, and born-digital materials). Calhoun discusses the growth of e-books, the importance of special collections and archives, the emergence of digitized research library collections (e.g., Europeana, HathiTrust) and discovery services (e.g., portals), and concludes with licensing, e-resource management, remote access, and finally the web visibility of hybrid libraries.

An examination of the book’s second theme begins with chapter 6, “Social Roles of Digital Libraries.” Calhoun considers the value of libraries to their communities, both past and present, and uses them as a framework to describe the social role of their digital counterparts. She emphasizes five key areas: to support the free flow of ideas, to empower individuals and reduce what is known as the digital divide (the gap between those with and those without access to digital information and its related technologies), to support teaching, learning, and the advancement of knowledge, to provide economic benefits (in the global economy, knowledge and networks feed the fire of innovation and economic growth), and to preserve the intellectual and cultural assets for future generations. By incorporating these areas into their framework, digital library managers should be able to describe their roles to external audiences such as funding bodies, in making priorities and improving service to their communities, and finally in defining desired outcomes and assessing the libraries in terms of their community impact. Chapters 7 and 8, “Digital Libraries and Their Communities” and “The Prospects of Open Access Repositories,” expand on the work begun in chapter six by looking at why some digital libraries continue to succeed while others fail, and focuses on the potential of digital library repositories to have a positive impact on scholarship and increase their social and economic value.

The last two chapters examine potential paths digital libraries can follow through the maze that is the social web. Chapter 9, “Digital Libraries and the Social Web: Scholarship,” examines how digital libraries can promote the importance of scholars’ work, and increase their avenues for collaboration. Finally, chapter 10, “Digital Libraries and the Social Web: Collections and Platforms,” expands on chapter 9 to examine the transition of collections to platforms that fit well with users’ expectations for finding information, reusing data for their own needs, inviting collaboration, and generally working and playing on the web. One possibility is through crowdsourcing to leverage user strengths and encourage their support of digital libraries’ future existence.

The book should be experienced in the digital realm, rather than under the limitations imposed by the physical (read “analog”) world. While it can be read from cover to cover, each chapter contains what could be considered hyperlinks that pinball the reader from like concept to like concept, no matter their physical relativity to each other within the book. This reviewer would not be surprised if future editions of this book will come to market as a digital download or permanent web link.

Another quote from the back cover, by Lorcan Dempsey, Vice President, OCLC Research and Chief Strategist, states that “this book provides an overview of the digital turn in libraries,” and “fills a clear gap in the library literature.” After reading Exploring Digital Libraries, the reviewer would have to agree. The book covers a plethora of topics about digital libraries within its 300-plus pages, while not overwhelming the reader in the process. The one complaint that this reviewer has is that the book is indeed an overview of the field, and some areas (such as streaming media) are skimmed over due to time and space constraints. This book is definitely recommended to library science students and educators, and those libraries trying to understand the digital world in which they now find themselves.