Microsoft have recently Open Sourced PowerShell and made it available for Linux and Mac.

https://github.com/PowerShell/PowerShell

To Install powershell on Ubuntu, go to
https://github.com/PowerShell/PowerShell/releases

Download latest release. To install PowerShell v6.0.0-alpha.17 Release, run

wget https://github.com/PowerShell/PowerShell/releases/download/v6.0.0-alpha.17/powershell_6.0.0-alpha.17-1ubuntu1.16.04.1_amd64.deb
dpkg -i powershell_6.0.0-alpha.17-1ubuntu1.16.04.1_amd64.deb

Bit install fails with some warning, i have to force it by running

apt install -f

To run powershell, run

powershell

root@SG1ZVJ0BOBY01:~# powershell
PowerShell 
Copyright (C) Microsoft Corporation. All rights reserved.

PS /root> get-help                                                                                                                                                                                          

TOPIC
    Windows PowerShell Help System

SHORT DESCRIPTION
    Displays help about Windows PowerShell cmdlets and concepts. 

LONG DESCRIPTION
    Windows PowerShell Help describes Windows PowerShell cmdlets,
    functions, scripts, and modules, and explains concepts, including
    the elements of the Windows PowerShell language.

    Windows PowerShell does not include help files, but you can read the
    help topics online, or use the Update-Help cmdlet to download help files
    to your computer and then use the Get-Help cmdlet to display the help
    topics at the command line.

    You can also use the Update-Help cmdlet to download updated help files
    as they are released so that your local help content is never obsolete. 

    Without help files, Get-Help displays auto-generated help for cmdlets, 
    functions, and scripts.


  ONLINE HELP    
    You can find help for Windows PowerShell online in the TechNet Library
    beginning at http://go.microsoft.com/fwlink/?LinkID=108518. 

    To open online help for any cmdlet or function, type:

        Get-Help  -Online    

  UPDATE-HELP
    To download and install help files on your computer:

       1. Start Windows PowerShell with the "Run as administrator" option.
       2. Type:

          Update-Help

    After the help files are installed, you can use the Get-Help cmdlet to
    display the help topics. You can also use the Update-Help cmdlet to
    download updated help files so that your local help files are always
    up-to-date.
    
    For more information about the Update-Help cmdlet, type:

       Get-Help Update-Help -Online

    or go to: http://go.microsoft.com/fwlink/?LinkID=210614


  GET-HELP
    The Get-Help cmdlet displays help at the command line from content in
    help files on your computer. Without help files, Get-Help displays basic
    help about cmdlets and functions. You can also use Get-Help to display
    online help for cmdlets and functions.

    To get help for a cmdlet, type:

        Get-Help 
    
    To get online help, type:
   
        Get-Help  -Online    

    The titles of conceptual topics begin with "About_".
    To get help for a concept or language element, type:

        Get-Help About_

    To search for a word or phrase in all help files, type:

        Get-Help 

    For more information about the Get-Help cmdlet, type:

        Get-Help Get-Help -Online

    or go to: http://go.microsoft.com/fwlink/?LinkID=113316


  EXAMPLES:
      Save-Help              : Download help files from the Internet and saves
                               them on a file share.
      Update-Help            : Downloads and installs help files from the
                               Internet or a file share.
      Get-Help Get-Process   : Displays help about the Get-Process cmdlet.   
      Get-Help Get-Process -Online
                             : Opens online help for the Get-Process cmdlet.                            
      Help Get-Process       : Displays help about Get-Process one page at a time.
      Get-Process -?         : Displays help about the Get-Process cmdlet.      
      Get-Help About_Modules : Displays help about Windows PowerShell modules.
      Get-Help remoting      : Searches the help topics for the word "remoting."

  SEE ALSO:
      about_Updatable_Help
      Get-Help
      Save-Help
      Update-Help













PS /root> exit                                                                                                                                                                                              
root@SG1ZVJ0BOBY01:~#