This will enable computers to automatically consume Web-based information, overcoming the human-centric focus of the Web as it stands at present, and accelerate the construction of a new class of intelligent knowledge-based applications will use Web content. this text is organized into three main sections on knowledge representation techniques, reasoning with multi-agent systems, and knowledge services. The main theoretical results underlying each technology is presented, and major problems and research issues that remain are summarized. Based on the courses 'Multi-Agent Systems and Semantic Web' taught at the University of Edinburgh, this text is ideal for final year students of undergraduate and postgraduate in Mathematics, Computer Science, Artificial Intelligence, and Logic and researchers interested in Multi-Agent Systems and Semantic Web.