Many engineering domains started using generic modeling languages, such as SysML, to describe or prescribe the systems under development. This raises a gap between the generic modeling languages and the domains of experience of the engineers using these. Engineering truly domain-specific languages (DSLs) for experts of these domains still is too challenging for their wide-spread adoption. One major obstacle, the inability to reuse multi-dimensional (encapsulating constituents of syntax and semantics) language components in a black-box fashion prevents the effective engineering of novel DSLs. To facilitate engineering DSLs, we devised a concept of 3D components for textual, external, and translational DSLs that relies on systematic reuse through systematic closed and open variability in which DSL syntaxes can be embedded, well-formedness rules joined, and code generators integrated in a black-box fashion. We present this concept, a method for its systematic application, an integrated collection of modeling languages supporting systematic language reuse, and an extensible framework that leverages these languages to derive novel DSLs from language product lines. These can greatly mitigate many of the challenges in DSL reuse and, hence, can advance the engineering of truly domain-specific modeling languages.