The availability of an increasing number of cloud offerings allows for innovative solutions in designing applications for the cloud and in adapting existing ones for this environment. An important ingredient in identifying the optimal distribution of an application in the cloud, potentially across offerings and providers, is a robust topology model that can be used for the automated deployment and management of the application. In order to support this process, in this work we present an application topology language aimed for cloud applications that is generic enough to allow the mapping from other existing languages and comes with a powerful annotation mechanism already built-in. We discuss its supporting environment that we developed and show how it can be used in practice to assist application designers.