There’s a new open source cloud in town. Meet Apache CloudStack

It looks like OpenStack won’t have the open-source cloud spotlight to itself anymore. Citrix Systems (s ctxs) has released its CloudStack software (which it obtained via its acquisition of last year) to the Apache Software Foundation, creating a competitive option to the OpenStack project of which Citrix was an early member. And while the move is ultimately part of Citrix’s corporate battle against VMware (s vmw) on the cloud-software front, it’s also very much a comment on the state of OpenStack.
OpenStack is the open source cloud-computing project founded by Rackspace and NASA in July 2010. It has since attracted dozens of high-profile contributors and users. Citrix was among the first users to sign on, followed by the likes of Cisco (c csco), HP (s hpq), Dell (s dell), AT&T (s T) and others. The goal of OpenStack is to provide a set of common building blocks for building an ecosystem of infrastructure-as-a-service (IaaS) public clouds that can compete with leaders such as Amazon Web Services (s amzn) and with proprietary private-cloud software like that sold by VMware and Microsoft (s msft).

CloudStack is for real

Assuming it gets traction with developers, CloudStack should present a formidable competitor for primary targets OpenStack and VMware, as well as fellow open-source cloud vendor Eucalyptus. The software already claims thousands of private IaaS clouds running atop it, including large production clouds at Zynga (s znga), Bechtel and GoDaddy. Those big names help explain why Citrix paid more than $200 million for in July.
And while the software was always open source — Peder Ulander, vice president of marketing in Citrix’s Cloud Platforms Group, claims more than 30,000 members in its online community — making CloudStack an Apache project is very important. OpenStack has been dogged by concerns over its Rackspace-heavy governance model since its inception, resulting in the project creating last October the independent OpenStack Foundation to take over project management. Apache, of course, is a well-respected open source foundation responsible for everything from the eponymous Apache HTTP Server to Hadoop.
OpenStack, for what it’s worth, actually uses the Apache open source license. It’s forthcoming Essex release, I’m told, includes contributions from more than 200 developers across 55 companies.
Ulander said CloudStack will launch with about 30 technology partners, many of which are already involved with OpenStack. “I expected a good reaction,” he said. “I didn’t expect [the] amazing reaction [we received].”

Insurmountable differences

According to Sameer Dholakia, vice president and general manager of the Cloud Platforms Group at Citrix, the decision to make CloudStack an Apache project wasn’t easy, but was necessary. “Our very explicit public statement had been that we were going to try and build atop the OpenStack platform,” he told me during a recent call. “… [But] we can’t afford to wait a year or two for the technical maturation process that needs to happen [in order to integrate CloudStack and OpenStack].”
Citrix tried to work with OpenStack, he said — it spent the better part of a 2011 trying to do that — but CloudStack software was 12 to 24 months ahead of OpenStack in terms of development, and the gap just wasn’t closing fast enough. OpenStack just isn’t stable enough for many customers wanting to run production clouds. “[We were] left with no choice but to double down [and pursue Apache CloudStack],” Dholakia said.
He also noted the difference in viewpoint between Citrix and OpenStack when it comes to the API layer. While OpenStack is pushing its own API, Dholakia called it “a tall and unnecessary order” to build another API when the Amazon Web Services API has become a de facto standard already.
Ulander suggested that Citrix will actually push for a tighter relationship with Amazon. The API-licensing agreement AWS entered into with Eucalyptus last month was non-exclusive, “and we’ll absolutely work to take advantage of that,” Ulander said.

OpenStack isn’t impressed

I spoke with one member of the OpenStack board who was less than impressed when he heard about Citrix’s decision, saying a lot of what he has heard “rings a little false.” Some of the technical gaps Dholakia cited had been raised, he said, but it was difficult to get specific details despite actually spending days working with Citrix to integrate the two platforms.
He doesn’t find the AWS compatibility too compelling, either, especially considering that OpenStack includes API compatibility with both Amazon EC2 and S3 and has since the beginning. And despite rumors of their demise, the forthcoming OpenStack Essex code release includes more than a hundred improvements to those APIs.
But OpenStack always wanted to be something more. “Anyone can take a piece of software, slap an API on it and build a clone,” he said, but OpenStack  is more complex by design. That might mean it’s more difficult to deploy (which is where OpenStack-based startups such as Piston Cloud Computing (see disclosure) and Nebula come in), but it also enables advanced networking capabilities and the ability to use OpenStack for complicated use cases such as high-performance computing.
And both projects share a common purpose of eating into VMware’s sizable mindshare lead in the world of cloud software. “I don’t know why we don’t do that together,” he said.
Disclosure: Piston is backed by True Ventures, a venture capital firm that is an investor in the parent company of this blog, Giga Omni Media. Om Malik, founder of Giga Omni Media, is also a venture partner at True.