Horizontal DSLs vs vertical

(Kleppe, A., 2008 35) Perhaps because the term domain is not clearly defined, people have been making distinctions between types of domains: broad versus in-house, technically oriented versus business-oriented, horizontal versus vertical. Broad, technically oriented, and horizontal mean more or less the same thing, which is that the DSL can be applied to a large group of applications that share the same technical characteristic, for instance “any Web application.” Characterizing a DSL as in-house, business oriented, or vertical usually indicates that the concepts in the DSL are not computer science concepts but instead come from the business in which computer science is applied. For instance, the concepts of Web page and database table come from computer science, whereas downcoming tray, hifi tray, and manhole are concepts used in oil distilleries, an industry in which computer science is applied (W. van Leeuwen and A. Kleppe, 2005) .