The Handbook of Semantic Web Technologies edited by John Domingue, Dieter Fensel and Jim Hendler has just been published by Springer. This two volume reference work contains 22 chapters spanning over 1000 pages covering all the essential areas of Semantic Web research today. The book was first conceived in the summer of 2008 when the editors along with Springer felt that the Semantic Web was moving into a mature phase whereby significant corporate interest was aligned with changes in the main funding streams. A reference was required to support the new phase. To this end an advisory board was setup which provided advice on structure and possible authors. This set composed of the advisory board and chapter authors comprised a very significant portion of the world’s leading researchers in the area including for example Chris Bizer, Tim Finin, Frank van Harmelen, Ian Horrocks, Mark Musen, Nigel Shadbolt, Guus Schreiber, Amit Sheth, Steffen Staab, Rudi Studer and Chris Welty. Besides editorship KMi also played a significant role in the work with chapter authors including: Harith Alani, Mathieu d’Aquin, John Domingue, Enrico Motta and Carlos Pedrinaci. The text is split into two volumes: the first covering the foundations of the Semantic Web and the second covering applications from both a technical and market perspective. Although early days the signs are that this tome will soon become the main reference work for the area.