Another cloud computing provider similar to eucaliptus: VMOps develops software that allows companies to launch an elastic computing cloud and offer it as a service to end-users.
An incredible article that dates back to 2007 explaining the emergence of what we now know as the Google Cloud, giving a thorough understanding of the concept
Vertebra is Engine Yard's "platform for developing and managing secure cloud applications", and was announced in June 2008. Now, it has finally been released-under the LGPL3.