Looking to build out its portfolio of cloud services, Amazon has partnered with Eucalyptus to deliver an Infrastructure as a Service (IaaS) product.

As part of the deal, Amazon Web Services (AWS) is letting the IaaS provider tap into its application programming interfaces (APIs). Eucalyptus says it is now “fully compatible with the Amazon Web Services API, which means you can use or reuse your existing AWS-compatible tools, images (AMIs), and scripts to manage your own hybrid and on-premise clouds.”

“We implement the AWS API on top of the Eucalyptus infrastructure, so a tool in the cloud ecosystem that communicates with AWS can communicate with a Eucalyptus cloud,” Eucalyptus notes on its site.

Eucalyptus’s IaaS service is now compatible with the following AWS services: EC2, EBS, AMI, S3, and IAM. Here’s how it fits together:

Eucalyptus’ IaaS is now compatible with AWS. Image: Courtesy of Eucalyptus

GigaOm’s Om Malik, who spoke to Eucalyptus CEO Marten Mickos about the deal, writes, “It was clearly a big shot in the arm for his company that started to face competition from many different quarters including the strong efforts of the OpenStack companies.”

While the move calls into question Amazon’s focus on the public cloud, it also makes clear that the hybrid cloud is a reality, and that to broaden its appeal to the enterprise, AWS has to embrace the private cloud.

“Amazon.com’s web services division is making a masterful move to dominate the cloud market,” Malik writes. But he also calls Amazon on softening its all-public stance on the cloud. “When asked if this was a tactical admission that Amazon needs a hybrid cloud option, Kay Kinton, a company spokesperson denied [that], saying ‘integration between on-premises infrastructure and the AWS cloud is a use case that’s important to some of our customers.’”

Does this move mean it’s game over for the public cloud in the enterprise? “Not at all and we believe that over time, most enterprises will not run their own datacenters and those that do will have a much smaller footprint,” Kinton told Malik.

Weigh in: Is Amazon making all the right moves to build out its cloud empire? Also, is Amazon going soft on its public cloud stance?