The ongoing transformation of the traditional power system into a more intelligent Smart Grid has many benefits. However, it also brings numerous challenges. The system is becoming more complex, making the existing domain specific tools less relevant. This paper presents a flexible co-simulation framework that supports multiple simulators, including multiagent platform, for a detailed evaluation of the impact and inter-dependencies between the cyber and physical components of the system. Two case studies have been evaluated with different Smart Grid applications, modeled and simulated with different simulators and coupled into the developed co-simulation framework. The results show the flexibility and useability of the proposed co-simulation framework.@en