Abstract. In domain-specific development model-driven development environments play an important role. Most of these environments only provide support for language engineering, but do not consider the second dimension which is concerned with domain engineering. In this paper, we join the concerns of language engineering and domain engineering towards a new comprehensive approach of domain-specific development. It allows domain designers to build domain models containing both, types and instances, and it allows language designers for defining language metamodels. Furthermore, based on the integrated description logics the environment provides services for productive modeling in domain and language engineering.