ConPaaS is a runtime environment for hosting applications in the cloud. It aims at offering the full power of the cloud to application developers while shielding them from the associated complexity of the cloud. ConPaaS is designed to host both high-performance scientific applications and online Web applications. It automates the entire life-cycle of an application, including collaborative development, deployment, performance monitoring, and automatic scaling. Finally, it runs on a variety of public and private clouds, and is easily extensible. This allows developers to focus their attention on application-specific concerns rather than on cloud-specific details.