Domain Specific Languages (DSL) have received some prominence recently. Designing a DSL and all their tools is still cumbersome and lots of work. Engineering of DSLs is still at infancy, not even the terms have been coined and agreed on. In particular globalization and all its consequences need to be precisely defined and discussed. This chapter provides a definition of the relevant terms and relates them, such that a conceptual model emerges. The authors think that this clarification of terms and the meaning will foster the field of ecient DSL definition and evolution in the future. 1 Towards a Conceptual Model Of Globalization Software Engineering, unlike other engineering disciplines, such as Civil, Chemical or Material, deals with constructing precise descriptions of highly complex systems, where each new application contains structure and behaviour that is essentially unique. In essence, each new application is a novel theory of structure and execution, and requires a way of expressing this meta-information [2]. Traditionally General Purpose Languages (GPLs) have been used to encode the theories in executable, but implicit forms (e.g., libraries). However recent advances in language engineering technologies have made it possible to develop Domain Specific Languages (DSLs) each of which is more suited to encoding theories relating to specific application domains [4]. Modern applications tend to be large, heterogeneous and distributed, involving the use of many di↵erent languages including mixtures of GPLs and DSLs. Given that an application consists of many di↵erent subsystems written in di↵erent languages, there is a requirement to ensure that the languages and therefore the subsystems work together e↵ectively and must share the same concepts (theories). Subsystems written in DSLs are attractive because the languages can provide better support for the specific application domains, however they tend to be less mature than their GPL counterparts and therefore there is an interesting research challenge: how to achieve language globalization [1]