Every released version of Microsoft Dos and microsoft windows (for personal computer) come with command line interface tools(Shell).shell is the command line interpreter which support only few commands.For other purpose we have to invoke another console application from shell . In shell we have scripting language called (batch File)which also have limitation to automate the things as we are unable to access all the GUI Functionalities of windows through batch file.
To overcome above defects Microsoft introduces windows script host that released with windows 98 ,its command line based is cscript.exe and it interacting with Active search engines that allow to written the script into compatible language like JScript,VBScript but still its was not interacted with shell.
To overcome this Microsoft worked with new project with help to introduce new command line management with shell .this approached was newly designed and suggested by MR Monad Manifesto and first Monad was released by Microsoft. Monad public beta release on June 17, 2005.
on April 25, 2006 Microsoft formally announced that Monad had been renamed Windows PowerShell, positioning it as a significant part of their management technology offerings.
What actually Monad Manifesto purpose check here original paper