Google App Engine SDK 1.4.3

Google App Engine SDK 1.4.3 brings users the opportunities of using an effective software which can 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 from your own domain name (such as http://www.example.com/) using Google Apps.

Or, you can serve your app using a free name on the appspot.com domain. You can share your application with the world, or limit access to members of your organization. Google App Engine supports apps written in several programming languages. With App Engine's Java runtime environment, you can build your app using standard Java technologies, including the JVM, Java servlets, and the Java programming language—or any other language using a JVM-based interpreter or compiler, such as JavaScript or Ruby. App Engine also features a dedicated Python runtime environment, which includes a fast Python interpreter and the Python standard library.

The Java and Python runtime environments are built to ensure that your application runs quickly, securely, and without interference from other apps on the system. With App Engine, you only pay for what you use. There are no set-up costs and no recurring fees. The resources your application uses, such as storage and bandwidth, are measured by the gigabyte, and billed at competitive rates. You control the maximum amounts of resources your app can consume, so it always stays within your budget. App Engine costs nothing to get started. All applications can use up to 500 MB of storage and enough CPU and bandwidth to support an efficient app serving around 5 million page views a month, absolutely free. 

1. Dynamic web serving, with full support for common web technologies
2. Persistent storage with queries, sorting and transactions
3. Automatic scaling and load balancing
4. Apis for authenticating users and sending email using google accounts
5. A fully featured local development environment that simulates google app engine on your computer
6. Task queues for performing work outside of the scope of a web request
7. Scheduled tasks for triggering events at specified times and regular intervals

• Added Files API that allows writing to and reading from files in blobstore.
• You can now specify cron execution for a time interval between a start and end time.
• You can now configure the specific application version to which a task queue or cron job will send requests.
• The Admin Console Task Queues page now displays a more accurate estimate of queue size for queues containing more than 2000 tasks.
• The Prospective Search API (formerly named the Matcher API) is available for use by all applications. This API is still experimental, so applications will be limited to a maximum of 1000 subscriptions.
• The Testbed API provides easy configuration of stub libraries for local integration tests.
• In the Images API, the quality parameter was added to the resize, rotate, horizontal_flip, vertical_flip, crop and im_feeling_lucky methods.
• Fixed an issue where static file serving in the dev_appserver didn't support etags.
• http://code.google.com/p/googleappengine/issues/detail?id=368
• An error is now raised when the script mapping in the app.yaml file is missing the .py file extension.
• http://code.google.com/p/googleappengine/issues/detail?id=976
• Fixed an issue where no link was displayed in the Admin Console blobstore viewer for an unnamed blob.
• Fixed an issue where the Admin Console data viewer couldn't edit entities with ByteString properties. http://code.google.com/p/googleappengine/issues/detail?id=2367
• Fixed an issue where the Admin Console crashed when using a non-ascii key_name. http://code.google.com/p/googleappengine/issues/detail?id=2451
• Fixed an issue filtering on key while using the --use_sqlite option with the dev_appserver. http://code.google.com/p/googleappengine/issues/detail?id=3232
• The Disable Application admin function has been button-ized. http://code.google.com/p/googleappengine/issues/detail?id=4323
• Fixed an SDK issue where debugging logging wouldn't correctly print URLFetch payloads. http://code.google.com/p/googleappengine/issues/detail?id=783
• Fixed an SDK issue where an incompatible line ending was used on blob upload. http://code.google.com/p/googleappengine/issues/detail?id=3328
• Added more graceful handling of the missing mapreduce.yaml file when the user has enabled the Datastore Admin but is not otherwise using the MapReduce framework. http://code.google.com/p/googleappengine/issues/detail?id=3903
• Fixed an issue where the method webapp_add_wsgi_middleware was no longer recognized. http://code.google.com/p/googleappengine/issues/detail?id=4236

• Python 2.5/ Java 5 or Java 6