If you want to deploy a private mega-cloud — that is, a cloud made up of at least 10,000 servers — don’t look to proprietary stacks, according to Simon Crosby, CTO of Citrix System’s Data Center and Cloud Division.

Speaking live in theCube from Citrix Synergy, Crosby told SiliconANGLE founder John Furrier that nobody, not even VMware with Project Redwood, can currently offer a stack capable of building a mega-cloud.

“There are no proprietary stacks in existence that you can purchase today that would allow you t build a mega cloud,” Crosby said. “VMware has not built a mega-cloud … ever. When I talk mega-cloud, I’m talking something the size of Zynga, which is as big as EC2 plus at least 10,000 servers.”

Crosby said Citrix is contributing to Open Stack to bring an open source stack to market capable of supporting mega-cloud deployments. Open Stack currently has around 200 engineers contributing to it, with Citrix supplying “20 to 30 every day,” Crosby said.

Citrix is no Johnny-come-lately to Open Stack, Crosby assured Furrier. In addition to its two dozen or so contributors, Citrix “owns the blueprint for networking services” in Open Stack, which is key to delivering multitenancy.

In a wide-ranging interview, Crosby also discussed his larger mission at Citrix. “Everything that Citrix does is about virtualization,” Crosby said.

He continued: “Our whole mission here is to empower users and get IT from being a horrible burden which locks down experience and doesn’t really change the security mantra of the enterprise into being far more service centric, delivering services that really deliver delight to their end users. That’s what we do.”

End-users don’t want to be tied to a desktop or workstation, he said. They want enterprise applications and data to follow them wherever they go, on whatever device they choose.

Whether it’s a BlackBerry, an iPad or an Android tablet, “It’s the cloud in your pocket that’s transforming IT much more than just virtualizing the data center,” Crosby said.

There are two types of cloud models emerging, he said. The first is “IT-ops-centric,” with IT staff managing virtualized servers in corporate data centers. The second is “dev-ops,” like that from Heroku, Crosby said. The latter is growing significantly faster than the former, and is producing significantly more innovation in the way of cloud-based apps, which is key for Crosby.

“I am 100% all over the idea that cloud is about innovation,” Crosby said.