It covers a broad spectrum of active research areas like Model Driven Engineering for SOA, Mobility and Services, Dynamic Web Service Discovery and Composition, Service Management, and Semantic Web, just to name a few. As Web services technology has become widely established in corporate computing applications, Web services research is very important and still very productive research domain. This book provides timely reports on the leading edge of this work by collecting selected and revised papers originally presented at the Workshop on Emerging Web Service Technology (WEWST) held in conjunction with the 4th European Conference on Web Services (ECOWS'06) December 2006 in Zurich, Switzerland. Acting as a natural extension to the main ECOWS conference, the main purpose of the workshop WEWST serve as a forum for providing early exposure and much needed feedback to grow and develop original research ideas and to appear in the Web Services community.