Cloud computing offers both an opportunity and a challenge to the application interoperability. In a cloud computing environment, it may be easier to integrate software applications than in the traditional enterprise computing environment, if they all run on the same cloud platform, especially, on a SaaS (Software-as-a-Service) platform, following a common programming model. However, making multiple applications running on different computing clouds would make it more difficult to deal with multiple cloud platforms and their differences. This paper presents a novel service and data management platform called DSP (Data Service Portal) in the cloud computing environment that facilitates the integration of applications by sharing their information in a loosely coupled manner. DSP enables applications to collectively exchange data through a platform in a fine-grained access control environment. The applications can work cooperatively, through the data sharing mechanism provided by the platform playing the role of a data broker, without being aware of each other's presence. An individual application can maintain its own data and run independently of the other applications in the platform. The data sharing mechanism enables the applications to offer (or subscribe to) a set of data to be consumed by (or produced by) the other applications in the platform. The platform publishes the data model along with APIs and guidelines for applications to adapt to the DSP platform and get to on-board to the platform for the subscriptions. © 2011 IEEE.