SaaS: Google Apps, Dropbox, Salesforce, Cisco WebEx, Concur, GoToMeeting. PaaS: AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com, Google App Engine, Apache Stratos, OpenShift. And IaaS: DigitalOcean, Linode, Rackspace, Amazon Web Services (AWS), Cisco Metapod, Microsoft Azure, Google Compute Engine (GCE).