He has been Steering Committee Chair and Member, Organizer and Program Chairman and Member of many international conferences and workshops on graph grammars, abstract data types and theory and practice of software development (TAPSOFT, ETAPS, ICGT). He is member of IFIP WG 1.3 (Found. of Syst. Spec.) and of the editorial boards of "Journal of Computer and System Science" (Academic Press), "Mathematical Structures in Computer Science" (Cambridge University Press), "Applied Categorical Structures", (Kluwer Academic Publishers), Fundamenta Informaticae (IOS Press), and “Journal of Integrated Design and Process Science” (Transact. of the SDPS). Moreover, he is editor of the "Formal Specification Column" in the Bulletin of the EATCS, editor of various special issues of journals and of volumes in World Scientific Publishing and in Springer Lecture Notes in Computer Science, and reviewer for several scientific and industrial projects including ESPRIT Basic Research and several other EU projects. He has received the honorary Kosterman Professorship at Leiden University (1993-94), the C. V. Ramamoorthy Distinguished Scholar Award from the Society for Design and Process Science (SDPS) in Pasadena 2002, and the ICGT Award for the Most Influential Paper in the Area of Graph Transformation Since 2⁵ Years, at ICGT 2010 in Enschede.