This book contains the best papers from the first two instances of the International Conference on Web Information Systems and Technologies (WEBIST 2005 and 2006), organized by the Institute for Systems and Technologies of Information, C- trol and Communication (INSTICC) in collaboration with the OMG (Object M- agement Group), held in Miami (USA) and Setubal (Portugal) respectively. The purpose of WEBIST is to bring together researchers, engineers and practit- ners interested in the technological advances and business applications of web-based information systems. It has four main topic...