This book constitutes revised selected papers from the 11th International Conference on Web Information Systems and Technologies, WEBIST 2015, held in Lisbon, Portugal, May 20-22, 2015, organized by the Institute for Systems and Technologies of Information, Control and Communication (INSTICC), and technically sponsored by the European Research Center for Information Systems (ERCIS). The purpose of the WEBIST series of conferences is to bring together researches, engineers and practitioners interested in technological advances and business applications of web-based information systems. The 17 full papers presented in this volume were carefully reviewed and selected originally 115 paper submissions. They were organized in topical sections names: web interfaces and applications; internet technology; society, e-business and e-government; web intelligence; and mobile information systems.