This document focuses on the diversity and evolution aspects of a language. It is expected that a DSML evolves over time but it is also expected that language engineers could re-use several of the concepts implemented. This thesis focuses on tackling problems of language evolution and re-usability. The dissertation proposes a framework that supports syntactical and semantical composition of domain specific concepts. A formal overview of the methodological aspects is presented. A description of a DSML for implementing these notions is also described. The main goal is to present the developments that cover all facets when providing semantics to DSML in order to support prototyping and a high level of re-usability. This thesis is based on a formal approach for the methodology description and provides a set of case studies. Using several standards in the Software Language Engineering community, we propose a coherent and integrated method for DSML prototyping development.