I love this. Write your Java EE app; then deploy to up to 20 virtual servers like this:
The servers are Amazon EC2 instances, charged by the hour.
The tool comes from Chris Richardson, author of POJOs in Action. It combines a Groovy framework called EC2Deploy with appropriate Amazon virtual machine images and a Maven plugin. He calls the combination Cloud Tools. More on EC2Deploy here. The Cloud Tools home page is here. Open source under the Apache License 2.0.
Great for testing, could be good for live deployment too, especially now that you can get proper support from Amazon.
See also Jeff Barr’s Amazon Web Services Blog.