What is AppScale?
AppScale is an open source cloud computing platform that supports the execution of applications developed by Google App Engine. AppScale can be used to upload multiple App Engine applications to a cloud.
AppScale Framework is a platform-as-a-service implementation. It is located above any virtualization-based infrastructure in order to host and operate applications created in the Google App Engine. It supports the delivery of multiple applications via the cloud and supports the delivery to large providers that work as infrastructure as a service. Prior to commercial release, the AppScale Framework was developed and maintained as a university research project in the Rapid Access Computing Environment Lab at the University of Santa Barbara.
AppScale is written in Java, Go and Python for the Google App Engine and runs on infrastructure-independent platforms. It works by implementing it as a virtual machine over any virtualized infrastructure, including Amazon EC2 and Eucalyptus private clouds. It also supports the integration of applications developed for the Google App Engine.
AppScale also supports other APIs such as MapReduce and the Message Passing interface. AppScale offers complete freedom in the choice of public, private or hybrid cloud infrastructures. It also supports many different data stores including MySQL Cluster, Memcache DB, and MongoDB.