This book contains a selection of the best papers from WEBIST 2008 (the Fourth International Conference on Web Information Systems and Technologies), held in Funchal, Madeira, in 2008, organized by the Institute for Systems and Technologies of Information, Control and Communication (INSTICC), and co-sponsored by the Wo- flow Management Coalition (WfMC). The purpose of the WEBIST series of conferences is to bring together researchers, engineers and practitioners interested in the technological advances and business - plications of web-based information systems. The series focuses on four main topic areas, covering different aspects of web information systems, including internet te- nology; web interfaces and applications; society, e-business, and e-government; and e-learning. WEBIST 2008 received 238 paper submissions from more than 40 countries on all continents. A double-blind review process was enforced, with the help of more than 200 experts from the international Program Committee, each of them specialized in one of the main conference topic areas. After reviewing, 32 papers were selected to be published and presented as full papers and 64 additional papers, describing work-- progress, as short papers for oral presentation only. Furthermore, 58 papers were p- sented as posters. The full-paper acceptance ratio was 13%, and the total oral paper acceptance ratio was 40%. Therefore, we hope that you find the papers included in this book interesting, and we trust they may represent a helpful reference in the future for all those who need to address any of the research areas mentioned above.