216 Copyright © 2013, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Chapter 8 INTRODUCTION In the context of language and software devel- opment, modeling is beginning to take a more prominent role. Model-based approaches con- sider models as first-class entities that need to be maintained, analyzed, simulated and otherwise exercised, and mapped into programs and/or other models by automatic model transformations. Domain Specific Languages (DSLs) them- selves can be seen as artifacts of the model-based approach for language engineering. Indeed, in a Paolo Arcaini Università degli Studi di Milano, Italy Angelo Gargantini Università di Bergamo, Italy Elvinia Riccobene Università degli Studi di Milano, Italy Patrizia Scandurra Università di Bergamo, Italy Formal Semantics for Metamodel-Based Domain Specifc Languages ABSTRACT Domain Specifc Languages (DSLs) are often defned in terms of metamodels capturing the abstract syntax of the language. For a complete defnition of a DSL, both syntactic and semantic aspects of the language have to be specifed. Metamodeling environments support syntactic defnition issues, but they do not provide any help in defning the semantics of metamodels, which is usually given in natural language. In this chapter, the authors present an approach to formally defne the semantics of metamodel-based languages. It is based on a translational technique that hooks to the language metamodel its precise and executable semantics expressed in terms of the Abstract State Machine formal method. The chapter also shows how different techniques can be used for formal analysis of models (i.e., instance of the language metamodel). The authors exemplify the use of their approach on a language for Petri nets. DOI: 10.4018/978-1-4666-2092-6.ch008