Recent years are characterized by a growing digitalization of production environment and other areas of human's life. Complex cyber-physical systems play a very important role within this development. Hence, integrated model-based design of such systems has gained significant attention. Quite naturally, this leads to the necessity of modeling hybrid system - systems containing both continuous-time and event-based phenomena. Hybrid modeling languages based on equations, supporting both continuous-time and eventbased aspects (e.g. Modelica, SysML, VHDL-AMS, and Simulink/Simscape) enable high-level reuse and integrated modeling capabilities of both the physically surrounding system and software for embedded systems. Using such equation-based object-oriented (EOO) modeling languages, it has become feasible to model complex systems covering multiple application domains at a high level of abstraction through reusable model components. They thus offer considerable advantages for many application areas. EOOLT is a forum for researchers with interests in all aspects of equation-based modeling languages and their supporting tools, including design, implementation, open issues limiting their expressiveness or usefulness, as well as novel applications.