Collaborative modelling and metamodelling with MetaEdit+

MetaEdit+ is a collaborative modelling tool and language workbench with a multi-user client-server object repository. Users, clients, server and repository can all be geographically distributed, and users access them with local apps, remote desktop or browser. Users can work with models and metamodels synchronously, with buffering via design transactions (minutes to hours), to prevent confusion and errors from releasing half-finished work. The tool uses automatic fine-granularity locking to avoid conflicts, allowing high concurrency. In this paper, we present an example case on which neophyte users can try this approach to collaboration in practice with minimal effort.