Preface The aim of COMMitMDE 2016 was to bring together experts in model-driven software engineering and collaborative software engineering to report on and discuss ongoing and future research and development related to collaborative modelling in MDE. In the context of MDE, a collaborative MDE approach is a method or technique in which: – models are the first-class elements that drive both the software development activities and the other model-based tasks in the context of a software engi- neering process; – at least one repository exists for managing the persistence of the models; – at least a modelling tool exists for allowing each stakeholder involved in the modelling activities to create, edit, and delete models; – at least a communication means exists for allowing involved stakeholders to be aware of what the other stakeholders collaborating with them are doing (e.g., chat, social network, wiki, asynchronous messaging system, issue tracker); – at least a collaboration means exists for allowing involved stakeholders to work on the modelling artifacts collaboratively (e.g., model versioning sys- tems, model merging mechanisms, systems for model conflicts management and visualization). The proceedings of COMMitMDE 2016 include four extended abstracts of in- vited talks delivered during the workshop, as well as five full papers. We would like to thank the members of the Program Committee of the workshop for their insightful reviews, as well as the invited speakers and authors for their contri- butions to an exciting programme. October 2, 2016 Henry Muccini St. Malo, France Ivano Malavolta Sebastien Gerard Dimitris Kolovos Program Committee Vincent Aranega Axellience, Lille, France Hans Vangheluwe University of Antwerp, Belgium and McGill Univer- sity, Canada Eugene Syriani University of Montreal, Canada Vincent Englebert University of Namur, Belgium Dustin Wüest University of Zurich, Switzerland Jean-Sebastien Sottet Luxembourg Institute of Science and Technology, Luxembourg Tihamer Levendovszky Microsoft, Seattle, USA Philip Langer EclipseSource Services GmbH, Vienna, Austria Manuel Wimmer University of Technology, Vienna, Austria Martina Seidl Johannes-Kepler-University, Linz, Austria Miguel A. Redondo Universidad de Castilla-La Mancha, Spain Mirco Franzago University of L’Aquila, Italy Ludovico Iovino Gran Sasso Science Institute, Italy Davide Di Ruscio University of L’Aquila, Italy Antonio Garcia-Dominguez University of York, UK Nicholas Matragkas University of Hull, UK Jordi Cabot ICREA, Spain Reda Brendaou LIP6, France