Voelter, MarkusEngels, GregorLuckey, MarkusPretschner, AlexanderReussner, Ralf2019-02-202019-02-202010978-3-88579-254-3https://dl.gi.de/handle/20.500.12116/20169In this paper I explain the benefits of projectional language workbenches for product line engineering. The ability to extend programming languages with domain specific concepts, mix programs (i.e. descriptions written in general purpose languages) and models (i.e. descriptions expressed with DSLs) and also overlay configurative variability to both of these promises highly integrated and productive tools for product line development.enText/Conference Paper1617-5468