A couple of Amazon's boys, credited with leading the development of EC2, have struck out on their own and launched Nimbula, whose purpose is to "blend EC2-like scale, agility and efficiency with private infrastructure customization and control."

Apparently the Silicon Valley-based Nimbula has been in stealth mode for over a year and brought in $5.75 million in Series A funding from Sequoia Capital and VMware.

And apparently it will be going after large organizations with a yen to have an EC2 of their very own.

Nimbula is starting with Nimbula Director, a so-called cloud operating system that manages on- and off-premise IT resources on customer-controlled infrastructure. It's supposed to be capable of linear scaling to thousands of nodes and automated hands-off installation and data center management. It promises metered bursting into public clouds like Amazon along with fine-grain policy-based authorization and network security.

The widgetry is reportedly in beta with a half-dozen international customers in financial services, tech and healthcare. Formal launch is set for the second half.

CEO Chris Pinkham, who used to be VP of engineering at Amazon, said Nimbula wants "to help customers see beyond the false dichotomy of public versus private clouds" and let them feel all warm and secure about cloud computing.

Nimbula's other co-founder now its VP of products Willem van Biljon wrote EC2's business plan and led its product development.

VMware co-founder and former CEO Diane Greene has just joined Nimbula's board.

The start-up's also got AWS' ex-biz dev and sales chief Martin Buhr as its VP of sales and ex-VMware exec Reza Malekzadeh as VP of marketing.