"Silicon Valley companies have difficulty coming to terms with the fact that a bookseller from Seattle is beating them to the punch when it comes to advanced distributed computing, which is what cloud computing essentially is," Mickos noted.

Mickos argued that the Amazon API has basically become a de facto standard for cloud computing that other vendors are adhering to, much like hardware manufacturers built IBM PC-compatible computers many years ago.

Public clouds and private clouds, software as a service, infrastructure as a service and platform as a service will all be necessary going forward, and open source software will give customers the flexibility to choose the rights tools for the job, Mickos said.

While and, to a lesser degree, VMware pursue vertical stacks characterized by what Mickos believes is lock-in and lack of choice, Eucalytpus created a flexible architecture offering customers their choice of hypervisor and operating system. By adhering to the Amazon API, Eucalyptus lets customers move workloads between private and public clouds, Mickos said.

Public clouds, like Amazon EC2, are further along than private clouds, but "both will be massive businesses" and complement each other, Mickos said. "We want to dominate the private cloud business and we're happy to see Amazon and others play for the public cloud."