Cloud Computing has become more and more prevalent over the past few years, and the authors have seen the emergence of Infrastructure-as-a-Service (IaaS) which is the most acceptable Cloud Computing service model. However, coupled with the opportunities and benefits brought by IaaS, the adoption of IaaS also faces management complexity in the hybrid cloud environment which enterprise users are mostly building up. A cloud management system, Monsoon proposed in this paper provides enterprise users an interface and portal to manage the cloud infrastructures from multiple public and private cloud service providers. To meet the requirements of the enterprise users, Monsoon has key components such as user management, access control, reporting and analytic tools, corporate account/role management, and policy implementation engine.