Contrail (http://contrail-project.eu/) develops an integrated approach to virtualization. It offers smart provisioning of resources over IaaS clouds through Virtual Execution Platform (http://vep.gforge.inria.fr/), provides services for federating IaaS clouds and Contrail Platform as a Service (ConPaaS) (http://www.conpaas.eu/) stack on top of federated clouds. Contrail technology also deploys the reliable cloud file system XtreemFS/GAFS (http://www.xtreemfs.org/) to provide location aware storage service. One of the primary objectives of Contrail is to offer performance (QoS) and security (QoP) guarantees via SLA enforcement, data location awareness, and a scalable management of the computing resources via an interoperable Federation. The first public release of the Contrail system is available (http://contrail.projects.ow2.org/xwiki/bin/view/Main/WebHome).