Microsoft Azure provides a platform level framework for rapidly building and deploying elastic cloud services and applications.
 
It is coupled into the Microsoft portfolio (Visual Studio, C#) but also supports other platforms such as PHP or Node.js.
It mirrors certain foundation features of AWS such as Virtual Machines, and Storage.
 
An interesting aspect of Azure is the components are better 'connected' and less descrete in their own way. So connecting an Azure WebRole developed in Visual Studio in C#, to a SQLAzure relation database, making full use of SQL 2008 features such as Spatial types is simple.