Microsoft Windows Azure

Windows Azure is a Microsoft cloud computing platform used to build, host and scale web applications through Microsoft data centers.The platform consists of various on-demand services hosted in Microsoft data centers and commoditized through three product brands: Windows Azure (an operating system providing scalable compute and storage facilities), SQL Azure (a cloud-based, scale-out version of SQL Server), and Windows Azure AppFabric (a collection of services supporting applications both in the cloud and on premise).

See the reference side-by-side comparison Platform as a service (PAAS) for cloud applications (Scalable cluster of services)