Preface to AEWSE'06

Current Web Applications are volatile in nature, and require (frequent) changes of content, functionality, semantics, structure, navigation, presentation or implementation. Often, the application is somehow engineered at design time to be able to adapt to for example the user, context, or device: this is reflected by the concept of adaptation. However, changes may also occur unexpectedly over time, for example in the case of a re-design of the site or in the case of updates due to changing external sources: in this case, we talk about evolution as a natural and intrinsic part of the application's life cycle.The First International Workshop on Adaptation and Evolution in Web Systems Engineering studies all forms of (support for) adaptation and evolution during the Web engineering process, and in particular the synergy between both.