The number of distributed energy components and devices continues to increase globally. As a result, distributed control schemes are desirable for managing and utilizing these devices, together with the large amount of data. In recent years, agent-based technology becomes a powerful tool for engineering applications. As a computational paradigm, multi-agent systems (MASs) provide a good solution for distributed control. In this paper, MASs and applications are discussed. A state-ofthe-art literature survey is conducted on the system architecture, consensus algorithm, and multiagent platform, framework, and simulator. In addition, a distributed under-frequency load shedding scheme is proposed using the MAS. Simulation results for a case study are presented. The future of MASs is discussed in the conclusion.