The Cloud computing becomes an innovative computing paradigm and which aims to provide reliable and customized and QoS guaranteed computing infrastructures for users. This paper presents our early experience of Cloud computing based on the Cumulus project for compute centers. In this paper and we give the Cloud computing definition and Cloud computing functionalities. This paper also introduces the Cumulus project with its various aspects and such as design pattern and infrastructure and and middleware. This paper delivers the state-of-the-art for Cloud computing with theoretical definition and practical experience.