Version 1.5 of the the Google App Engine adds an experimental runtime for the Go Programming language which enhances its status as a language that is moving forward.

Google's App Engine still has Preview status even though it now hosts more than 200,000 active apps and is used by more than 100,000 developers a month.

It is expected to "graduate" later this year at which time it will have enterprise-grade features to support more business application scenarios. New features announced at Google I/O contribute to this business focus:

New backends for Python and Java will allow App Engine to support for applications that require long running and high memory processes. This feature allows for new classes of applications such as report generation apps and custom search engines to be hosted on the platform.

Improvements to Task Queues allow applications to control how tasks are executed and to share the work using the new REST-based APIs. According to the Google App Engine blog:

You can now perform offline processing on App Engine by scheduling bundles of work (tasks) for automatic execution in the background. You don't need to worry about managing threads or polling - just write the task processing code, queue up some input data, and App Engine handles the rest. If desired, you can even organize and control task execution by defining custom queues.

This API access expands App Engine's compatibility with other on-premise and cloud services, furthering Google's commitment to an open development platform.

The new App Engine SDK is available for the open source language Go in addition to Python and Java. This indicates a significant change in the status of Go from an experimental in-house language to one that is ready for the wider world.

In the Google Code Blog, Scott Knaster comments that Go is

"as an interesting new option for App Engine because Go apps will be compiled to native code, making Go a good choice for more CPU-intensive tasks. Plus the garbage collection and concurrency features of the language, combined with excellent libraries, make it a great fit for web apps."

App Engine SDK for Go is available for download, and Google will shortly enable deployment of Go apps into the App Engine infrastructure. Developers who are interested in starting early are invited to sign up to be among the early testers. In common with Google's normal practice it is going to remain an experimental App Engine feature for some time.

A new pricing structure will come into force when App Engine comes out of preview in the second half of this year. While there will still be a Free Apps facility usage type quotas will be more restrictive. In addition to Paid Apps a new Premier Accounts offering is available for companies that prefer a flat fee and to be eligible to purchase support, see details of the new pricing model.

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