This online encyclopedia can be seen as the 21st century’s version of earlier historical attempts to gather the world’s knowledge into one place – this unique book offers a description of some of these earlier attempts. O’Sullivan follows with a thorough analysis of Wikipedia itself, suggesting on how to approach and contribute to the site and what can be gained by using it. Written in an accessible style, the author takes a socio-historical approach, arguing that by looking at communities of practice in the past we can come to understand the radical, even political, nature of Wikipedia. The book will have a broad appeal to anyone interested in the development of this unique project, including information management professionals, historians, sociologists, educators and students.