tsuru is a platform as a service with a component-oriented architecture. It provides application orchestration and instrumentation via an extensible interface for support multiple IAAS tools (currently working with Amazon AWS) and deployment management using Git.
AppScale is a platform that allows users to deploy and host their own Google App Engine applications. It executes automatically over Amazon EC2 and Eucalyptus as well as Xen and KVM. It supports the Python, Java, and Go Google App Engine platforms.