AppScale is an open-source framework for running Google App Engine applications. It is an implementation of a cloud computing platform (Platform-as-a-Service), supporting Xen, KVM, Amazon EC2 and Eucalyptus. It has been developed and is maintained by the RACELab at UC Santa Barbara. AppScale allows users to upload multiple App Engine applications to a cloud. It supports multiple distributed backends such as HBase, Hypertable, Apache Cassandra, and MySQL Cluster. It has support for Python, Go, and Java applications, taking the open source SDK provided by Google App Engine and implementing scalable services such as the datastore, memcache, blobstore, user's API, and channel API.