SaaS is the foundation of cloud computing. A provider usually has applications or services on offer that expose themselves to the end user through clients such as mobile devices, thin clients, or frameworks on other clouds. From a user point of view, the SaaS layer is virtually running on their client. This software abstraction has enabled the industry to achieve substantial growth in the cloud. SaaS services include such name brand appliances as Google Apps, Salesforce, and Microsoft Office 365.