Cloud computing has now crossed the frontiers of research to reach industry. It is used every day , whether to exchange emails or make reservations on web sites. However, many research works remain to be done to improve the performance and functionality of these platforms of tomorrow. In this talk, I will do an overview of some these theoretical and appliead researches done at INRIA and particularly around Clouds distribution, energy monitoring and management, massive data processing and exchange, and resource management.