With mature development of wired and wireless communications technologies, a variety of applications based on systems with the technologies have emerged. The industry in which time-to-market has become a significant factor requires conditions under which network applications are able to be developed as rapidly as possible. As the network applications are executed in wired and wireless communications system environment where multiple nodes are distributedly arranged, it takes enormous amounts of time and efforts to verify such applications in a real environment. Therefore, to address such an issue, this paper proposes a simulator that makes it possible to execute and verify network applications in a virtual environment. With repect to performance, the proposed integration simulator shows high process performance, because the integration of simulators led to the additional operation cost of 10% only. With regard to functions, it makes real network appliations executed easily, because it provides an interface highly similar to one in common operating systems.