This paper presents Occopus, an open-source cloud orchestration and management framework for heterogeneous multi-cloud platforms. Occopus provides a language to specify infrastructure descriptions and node definitions based on which Occopus can automatically deploy and maintain the specified virtual infrastructures in the target clouds. The paper introduces the required structure of the infrastructure descriptions and node definitions in an informal way and shows two use cases (Hadoop cluster and MICADO framework) how Occopus can be used to deploy complex virtual infrastructures. The paper also explains the architecture and implementation aspects of Occopus and describes its main distinguishing features compared to other cloud orchestrator frameworks.