The Google App Engine SDK will let you run your web applications on Google's infrastructure. 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 your users.
You can serve your app using a free domain name on the appspot.com domain, or use Google Apps to serve it from your own domain. You can share your application with the world, or limit access to members of your organization.
App Engine costs nothing to get started. Sign up for a free account, and you can develop and publish your application for the world to see, at no charge and with no obligation. A free account can use up to 500MB of persistent storage and enough CPU and bandwidth for about 5 million page views a month.

Limitations:
· Not only is creating an App Engine application easy, it's free! You can create an account and publish an application that people can use right away at no charge, and with no obligation. An application on a free account can use up to 500MB of storage and up to 5 million page views a month.
· During this preview period, only free accounts are available. In the near future, you will be able to purchase additional computing resources at competitive market prices. Free accounts will continue to be available after the preview period.
· During this preview period, you can register up to 3 applications.
· Application resource limits, or "quotas," are refreshed continuously. If your application reaches a time-based quota, such as bandwidth, the quota will begin refreshing immediately at the rate for the given limit. Fixed quotas such as storage use are only relieved when you decrease usage.
· Some features impose limits unrelated to quotas to protect the stability of the system. For example, when an application is called to serve a web request, it must issue a response within a few seconds. If the application takes too long, the process is terminated and the server returns an error code to the user. The request timeout is dynamic, and may be shortened if a request handler reaches its timeout frequently to conserve resources.
· Another example of a service limit is the number of results returned by a query. A query can return at most 1,000 results. Queries that would return more results only return the maximum. In this case, a request that performs such a query isn't likely to return a request before the timeout, but the limit is in place to conserve resources on the datastore.
· Attempts to subvert or abuse quotas, such as by operating applications on multiple accounts that work in tandem, are a violation of the Terms of Service, and could result in apps being disabled or accounts being closed.

What's New in This Release:
· The Sockets API, which allows applications to make outgoing TCP connections and send/receive UDP packets to the Internet using both IPv4 and IPv6, is now available as an experimental feature for billed apps.
· The ftplib module is now restored. It depends on the experimental Sockets API.
· Billing enabled apps will no longer be subject to a $2.10 minimum weekly spend. Instead, apps will only be charged for their actual usage.
· Matplotlib 1.1.1, an experimental feature, is being deprecated and will be removed in 1.7.8. Please switch to matplotlib 1.2.0.
· Fixed an issue where the dev_appserver Datastore auto ids assigned by the scattered id policy were too large to be represented as floating point numbers.
· Fixed an issue where the dev_appserver threw an exception on any Search API call that used an index that was originally created as GLOBALLY consistent.
· Fixed an issue with NDB not serializing projection entities correctly.
· Fixed an issue with NDB not projecting structured properties...