Windows Azure

Azure
Microsoft's Azure Services Platform is a cloud platform (cloud computing platform as a service) offering that "provides a wide range of internet services that can be consumed from both on-premises environments or the internet". It is significant in that it is Microsoft's first step into cloud computing following the recent launch of the Microsoft Online Services offering. A Community Technology Preview (CTP) was given to PDC 2008 attendees. This preview is set to expire in the 2nd quarter of 2009. The platform suffered its first major outage lasting 22 hours from March 13 2009, leaving all applications slow to start or restart, or simply hanging in "stopped" or "initializing" states.

Overview
The idea and push from Microsoft to compete directly in the software as a service model that Google's Google App Engine and Amazon's EC2 have offered is increasingly seen by them and others as an important next step in application development. In this idea, software doesn't have to be installed and managed on the user's computer. It also allows files and folders to be accessed from the web.

Implementation The Azure Services Platform uses a specialized operating system, Windows Azure, to run its "fabric layer" — a cluster hosted at Microsoft's datacenters that manages computing and storage resources of the computers and provisions the resources (or a subset of them) to applications running on top of Windows Azure. Windows Azure, which was known as "Red Dog" during its development, has been described as a "cloud layer" on top of a number of Windows Server systems, which use Windows Server 2008 and Hyper-V to provide virtualization of services.The platform includes five services — Live Services, SQL Services, .NET Services, SharePoint Services and Dynamics CRM Services — which the developers can use to build the applications that will run in the cloud. A client library, in managed code, and associated tools are also provided for developing cloud applications in Visual Studio. Scaling and reliability are controlled by the Windows Azure Fabric Controller so the services and environment don't crash if one of the servers crash within the Microsoft datacenter and provides the management of the user's web application like memory resources and load balancing. The Azure Services Platform can currently run .NET Framework applications written in C#, while supporting the ASP.NET application framework and associated deployment methods to deploy the applications onto the cloud platform. Two SDKs have been made available for interoperability with the Azure Services Platform: The Java SDK for .NET Services and the Ruby SDK for .NET Services. These enable Java and Ruby developers to integrate with .NET Services.

Source: http://en.wikipedia.org/wiki/Azure_Services_Platform