It’s live, it’s buggy, it’s beta.
Check it out:

http://novacc.org

From the website:

Nova is a cloud computing fabric controller (the main part of an IaaS system) built to match the popular AWS EC2 and S3 APIs. It is written in Python, using the Tornadoand Twisted frameworks, and relies on the standard AMQP messaging protocol, and the Redis distributed KVS.

Nova is intended to be easy to extend, and adapt.