Windows PowerShell is an extensible command line interface shell and associated scripting language from Microsoft.
Windows PowerShell integrates with .NET Framework and provides an environment to perform administrative tasks by execution of cmdlets (pronounced commandlets) which are specialized .NET classes implementing a particular operation, scripts which are composition of cmdlets along with imperative logic, executables which are standalone applications, or by instantiating regular .NET classes. These work by accessing data in different data stores, like filesystem or registry, which are made available to the PowerShell runtime via Windows PowerShell providers.
Windows PowerShell also provides a hosting mechanism with which the Windows PowerShell runtime can be embedded inside other applications, which can then leverage Windows PowerShell functionality to implement certain operations, including those exposed via the graphical interface. This capability has been utilized by Microsoft Exchange Server 2007 to expose its management functionality as PowerShell cmdlets and providers and implement the graphical management tools as PowerShell hosts which invoke the necessary cmdlets. Other Microsoft applications including Microsoft SQL Server 2008 also expose their management interface via PowerShell cmdlets. In the future, graphical interface-based management applications on Windows will be layered on top of Windows PowerShell.
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