Citrix is making a big announcement today. It has two parts. First, it's moving its CloudStack framework, which was owned by Citrix and distributed at CloudStack.org through a GPL license, to the Apache Foundation. Second, it is aligning CloudStack withAmazon Web Services' architecture and APIs.

This is big news that's sure to ruffle some feathers in the cloud computing space. So the questions I have are:

• Why are they doing this?
• What are the implications?

Why Is Citrix Moving CloudStack to the Apache Foundation?

The move appears straightforward. Citrix acquired CloudStack through its $200 millionacquisition of Cloud.com in July 2011. From what I'm hearing, it has had good success with enterprise and provider adoption of the product, but it was far from being accepted as an industry de facto standard, which is what, I assume, they had hoped for. So it would make sense for them to move it to a respected open source foundation like Apache.

But wait. There was already a OpenStack vying for that de facto standard open source platform status, and Citrix announced its support for it two months before the Cloud.comacquisition. The company said it would continue to support both platforms after the acquisition, so what happened?

Citrix claims that the OpenStack foundation wasn't run well: it was dominated by Rackspace and had a "pay-to-play" model. The result was that the APIs were poorly designed and the product lacked stability and maturity (a claim I have heard from others). At the same time, while OpenStack is getting support from the likes of Cisco and HP, the community is somewhat fragmenting, with multiple distributions and extensions from the likes of startups Cloudscaling and Piston Cloud. This started creating a problem for enterprise customers and providers who were getting confused and having a bad experience with OpenStack.

In the meantime, Citrix is feeling competitive pressure from the company it views as its primary rival for actual customers (as opposed to winning the hearts and minds of the "community"): VMWare.

It simply couldn't wait and had to go on the attack with a bold move. This is it -- and it's a pretty good one.

Why Align CloudStack with the AWS APIs?

The final piece in making CloudStack the de facto standard cloud platform is the API. By aligning with the Amazon APIs, CloudStack gains a hghly-adopted, proven API with a massive ecosystem of integrated tools and services around it. They tell me they will have 100% compatibility by the end of this year.

But the catch is this comes on the heels of Eucalyptus's announcement that it is aligning with the AWS APIs. Eucalyptus, just a reminder, is another open source cloud platform that has been vying for leadership among enterprise customers.

Game of Clouds

With this move complete, Citrix has a production-proven stable product, which is now an open source platform managed by the widely-respected Apache Foundation, using a popular API with a massive ecosystem around it. Pretty clever, I think.

On the other hand, CloudStack is fighting on three fronts now: its traditional arch-enemy VMWare, the OpenStack camp with the dozens of vendors -- large and small -- behind it, and Eucalyptus. A regular game of thrones. And to paraphrase Game of Thrones: In the Game of Clouds, you either win or you die.