Many challenges were identified in CSCW some thirty years ago, and some of these remain problematic today. However they are being progressively transformed and this edited volume contains contributions that demonstrate how these new challenges are being dealt with in a variety of ways, reflecting the balance of rigour and creativity that has always characterised the field. Originally presented at COOP '08 which took place in Carry-le-Rouet, France in 2008, the contributions to this volume have been substantially extended and revised. New techlogies, new domains and new methods are described for supporting design and evaluation. Taking a progressive and critical stance, the authors cover a variety of themes including inter-organisational working, n task-based environments, creativity, and the development of Web 2.0 (and even Web 3.0) applications, including new cooperative mechanisms and new classification possibilities.