Design Guidelines The various design guidelines we will discuss below, can

be organized into several categories. Essentially, these guide- lines describe techniques that are useful at different activities of the language development process, which range from the domain analysis to questions of how to realize the DSL to the development of an abstract and a concrete syntax including the definition of context conditions. An alignment of guide- lines with the language development activities and the de- veloped artifacts has the advantage that a language designer can concentrate on the respective subset of the guidelines at each activity. This should help identifying and realizing the desired guidelines. Therefore, we decided for a development phase oriented classification and identified the following cat- egories:

Language Purpose discusses design guidelines for the early activities of the language development process.

Language Realization introduces guidelines which discuss how to implement the language.

Language Content contains guidelines which focus on the elements of a language.

Concrete Syntax concentrates on design guidelines for the readable (external) representation of a language.

Abstract Syntax concentrates on design guidelines for the internal representation of a language.

For each of these categories we will discuss the design guidelines we found useful. Please be aware that the subse- quently discussed guidelines sometimes are in conflict with

each other and the language developer sometimes has to bal- ance them accordingly. Additionally, semantics is explicitly not listed as a separate step as it should be part of the entire development process and therefore has an influence on all of the categories above.

2. DSL DESIGN GUIDELINES

2.1 Language Purpose Language design is not only influenced by the question of

what it needs to describe, but equally important what to do with the language. Therefore, one of the first activities in language design is to analyze the aim of the language.