In cloud environments, the process of matching requests from users with available computing resources is a challenging task. This is even more complex in federated environments, where multiple providers cooperate to offer enhanced services, suitable for distributed applications. In order to resolve these issues, it is imperative to adopt a powerful modeling methodology that can facilitate expressing both the request and the available computing resources. This, in turn, leads to an effective matching between the request and the provisioned resources. For this purpose, the Open-MultiNet ontologies were developed, which leverage the expressive power of Semantic Web technologies to describe infrastructure components and services. These ontologies have been adopted in a number of federated testbeds. In this article, DBcloud is presented, a system that provides access to Open-MultiNet open data via endpoints. DBcloud can be used to simplify the process of discovery and provisioning of cloud resources and services.