Agile software development is now in its teens. It began by performing in relatively small pioneering organizations; then it gained the interest of medium-size companies, academia, and applied research institutions and laboratories; nowadays it runs in organizations of any kind, including major software and systems development companies. Because of such a wide diffusion of Agile in industry, the need for collaboration between academics and practitioners increases, in the aim of improving the body of knowledge available to help managers, system engineers, and software engineers to take their managerial/economical, and architectural/project / technical decisions. During its 15 editions, the XP conference has been a major suppo...