Abstract. It is still the case that language descriptions have lots of semantic information captured using plain (English) text. These imprecise descriptions are hardly usable for tools to generate language environments out of the language standard. SDL has already managed to define syntax and semantics in a quite formal way. Currently, this formality is usually connected to using grammars in one way or the other. On the other hand, meta-models have proven to be a good way of expressing complex facts and relations. Moreover, there are tools and technologies available realising all language aspects based on completely formal and still easily understandable descriptions. This paper reports about the experiment to define a complete meta-model-based language definition of (a subset of) SDL and to immediately have tool support for the language. This experiment includes the language aspects concrete syntax representation, static semantic constraints, and language behaviour. It turns out t...