Abstract—Concurrency is of primary interest in the development of complex software-intensive systems, as well as thedeployment on modern platforms. Furthermore, Domain-Specific Languages (DSLs) are increasingly used in industrial processes toseparate and abstract the various concerns of complex systems.However, reifying the definition of the DSL concurrency remainsa challenge. This not only prevents leveraging the concurrencyconcern of a particular domain or platform, but it also hinders:a) the development of a complete understanding of the DSLsemantics; b) the effectiveness of concurrency-aware analysistechniques; c) the analysis of the deployment on parallelarchitectures. In this paper, we present M oCCML, a dedicatedmeta-language for formally specifying the concurrency concernwithin the definition of a DSL. The concurrency constraintscan reflect the knowledge in a particular domain, but also theconstraints of a particular platform. MoCCML comes with acomplete language workbench to help a DSL designer in thedefinition of the concurrency directly within the concepts of theDSL itself, and a generic workbench to simulate and analyzeany model conforming to this DSL. Mo CCML is illustrated onthe definition of an lightweight extension of SDF (SynchronousData Flow).