In addition, while Eucalyptus is open source software, the development process of the software isn't open, he said. Users of OpenStack can more easily have features they want added to the stack, he said.
There are many APIs for using AWS, and OpenStack supports some of them. Eucalyptus doesn't support all of them either, but this new agreement suggests that Amazon will help it support more of them.
While the legal threat of using those APIs still hangs over any other software using them, including OpenStack, the organization isn't likely to bridge a similar deal with Amazon, O'Grady said. "OpenStack is not likely to either ask for or receive the same blessing from Amazon that Eucalyptus received," he wrote.
Some OpenStack distributions might like to have Amazon's blessing, but McKenty doesn't "think the community as a whole has an opinion on wanting a similar relationship with AWS."
One thing is certain: The deal crystalizes the competitive landscape. "This cements the perception that it's Amazon and Eucalyptus versus OpenStack and everyone who's not Amazon, with the notable exceptions of Joyent, Microsoft and VMware, each of whom owns and sells their own cloud stack," O'Grady wrote.