Book excerpt: A complex series of extensions to the World Wide Web, the Semantic Web's purpose is to make data and services far more accessible to computers and far more useful for people than the web we know today. Written for developers and programmers, this guide seeks to acquaint these users with the basic technologies and their interrelations that will be likely to play key roles in the Semantic Web. Covered are key technology areas such as knowledge modeling (RDF, Topic Maps), agents (DAML, FIPA), and Trust and Authentication. A basic conceptual approach is taken so that developers and programmers with a wide range of backgrounds and interests come to understand the essential nature of these areas, how they work, and something about some specific technologies that are being used or proposed. Important points are illustrated with diagrams and code fragments to help develop a familiarity with these Semantic Web initiatives.