A group of engineers who helped create Amazon.com's Elastic Compute Cloud service announced plans today to build a new cloud operating system that could compete with offerings from Microsoft and IBM.

Their company, Nimbula, is based in Menlo Park, Calif.. It has 17 employees and $5.75 million in funding from Sequoia Capital and VMWare.

Chris Pinkham, co-founder and chief executive (below), said Nimbula doesn't compete with his former employer and will actually be "an on ramp for EC2."

"We don't think this is directly competitive," he said. "We think this is complementary.''

Nimbula is developing software that runs within a company's network and directs where applications are run -- in-house or on various cloud services -- based on policies created by administrators. It's installed on top of an open-source hypervisor, and pitched as a way for companies to maintain the security of their information while taking advantage of cloud computing where appropriate.

The software is being tested by a set of unidentified companies in the finance, technology and healthcare fields. A beta version launches next quarter and it will be generally available in Q4.

Pinkham was vice president of Amazon's global infrastructure before managing development of EC2. To be closer to family, he left Seattle in 2005 for his native Cape Town, South Africa, where he set up an Amazon engineering office. He left the company in 2006, shortly before EC2 launched, and then started Nimbula in 2009.

Co-founder Willem van Biljon worked on EC2 product management and marketing. Nimbula's sales vice president, Martin Buhr, previously did EC2 business development and sales and before that worked at Microsoft.

"As the team leaders behind EC2, no one has a greater understanding of this emerging architecture and how to adapt it to enable large organizations to fully benefit from the co-existence of public and private cloud services," Sequoia general partner Roelof Botha said in a release.

Perhaps Botha's also enthusiastic because he, Pinkham and van Biljon all graduated from the University of Cape Town -- as did VMWare Chief Executive Paul Maritz.