Microsoft Powershell is a command line scripting language made for admininstrators . Powershell includes a large set of built in commands having consistent interface that works with user written commands .

Microsoft has released the Windows PowerShell Language Specification Version 2.0 which includes a docx file .

This means that the Windows Powershell Language Specification being shared to the community and the power shell is being licensed under Microsoft Community Promise .

The PowerShell Team states that

This means that now anyone can implement PowerShell on any platform they want to.  We know some of our most passionate customers sometimes work on platforms that can’t run PowerShell today, so when writing this specification, we wrote it in a platform neutral manner.

You can download the Windows PowerShell Language Specification Version 2.0 from the Microsoft Download Center

Know more about the announcement in the Windows PowerShell Blog