New language elements are introduced in Modelica 3.1 to facilitate use Modelica models in embedded systems, e.g., as controllers. Models can be conveniently configured by marking the borders of the respective controller parts and by defining the mapping of the marked parts to target processors and target tasks. This approach allows to define a “logical” model from which all different “real” controller configurations for Model-, Software-, Hardware-in-the-Loop (MiL, SiL, HiL), rapid prototyping, and production code for multi-processing/multi-tasking are automatically derived by setting configuration options. Furthermore, a new, free library - Modelica_EmbeddedSystems - is presented that provides a convenient user interface to the new language elements. In summary, the power of Modelica in the area of realtime control is improved significantly.