PowerShell goes beyond Windows.
PASH is the open source re-implementation of PowerShell for non-Windows operating systems like Solaris, Linux, Mac, etc and even Windows Mobile.
According to the site:
The main goal is to provide a rich shell environment for other operating systems as well as to provide a hostable scripting engine for rich applications. The user experience should be seamless for people who are used to Windows version of PowerShell. The scrips, cmdlets and providers should runs AS-IS (if they are not using Windows-specific functionality). The rich applications that host PowerShell should run on any other operating system AS-IS. Secondary goal: the scripts should run across the machines and different OS’s seamlessly.
Check out PASH at Sourceforge.