Abstract. One of the main goals of model-driven engineering (MDE) is the manipulation of models as exclusive software artifacts. Model execution is in particular a means to substitute models for code. More precisely, as models of a dedicated domain-specific modeling language (DSML) are interpreted through an execution engine, such a DSML is called interpreted-DSML (i-DSML for short). On another way, MDE is a promising discipline for building adaptable systems based on models at runtime. When the model is directly executed, the system becomes the model: This is the model that is adapted. In this paper, we propose a characterization of adaptable i-DSML where a single model is executed and directly adapted at runtime. If model execution only modifies the dynamical elements of the model, we show that the adaptation can modify each part of the model and that the execution and adaptation semantics can be changed at runtime.