Modifications are generally severely limited.

PaaS provides a model that can be used to create or augment complex applications such as Customer Relation Management (CRM) or Enterprise Resource Planning (ERP) systems.

VMM manages I/O for the virtual machines.

AWS has several data centers in which servers run on top of a virtualization platform (Xen).

Athenahealth is used for the medical industry.

More secure authentication requires the use of at least two-factor authentication.

Most of the cloud computing compliance systems to date have been built using private clouds.

There may be executable client-side code, but the user isn't responsible for maintaining that code or its interaction with the service.

The vendor of the PaaS solution is in most cases the developer, who is offering a complete solution to the customer.

The Identity Governance Framework (IGF) is a standards initiative of the Liberty Alliance.