If you have been following developments in software engineering in recent years, you have probably noticed that the term DSL (domain-specific language) has become a minor buzzword in that field. You may have concluded that this is a hot new idea that is certainly not ready for application in real life. But, as I will show in this article, computational scientists (and others) have been using DSLs for decades. What is new is not DSLs per se, but the name and the attention given to them.