Google App Engine made deployment, autoscaling, managed storage, and runtime constraints part of a hosted programming platform, helping define the platform-as-a-service model for cloud applications.
Rackspace and NASA launched OpenStack in 2010 by combining cloud storage and compute projects under an open-source community, creating a large vendor-neutral infrastructure platform.
Amazon EC2's 2006 beta exposed virtual machines through a web-service interface with rapid provisioning and usage-based billing, helping turn infrastructure capacity from a procurement decision measured in servers into an API-driven resource measured in instance-hours.