External Textual DSLs are a sweet spot in DSL-land: their textual nature allows for simple integration with existing development infrastructures (such as CVS or SVN). Being external, they are not limited by the syntax of a host language and can provide static ("compile time") error checking. Traditionally, the drawback of this kind of DSL was that the construction of the grammar and a fancy editor was quite a lot of work.

In this session I will briefly talk about the tradeoffs between textual/graphical/internal/external DSLs and then proceed to build a textual DSL, complete with a syntax coloring, code completing and constraint checking editor. We will then look at how to process the "program" written in the DSL by either writing a compiler (aka code generator) and an interpreter.

The goal of the session is to convince the audience that building an external textual DSL is easier and better than working with XML! The examples will use Eclipse TMF/openArchitectureWare tooling.