According to http://code.google.com/appengine/:
"Google App Engine enables you to build web applications on the same scalable systems that power Google applications. App Engine applications are easy to build, easy to maintain, and easy to scale as your traffic and data storage needs grow. With App Engine, there are no servers to maintain: You just upload your application, and it's ready to serve to your users."
Ever since Google offered the Google App Engine (GAE) platform, it has revolutionized the industry giving birth to a game changing concept–Cloud Computing.
Google App Engine (as we know it today) lets you develop server hosted web applications in Python and Java based on the Google App Engine APIs ...