Microsoft has announced that PowerShell is now open source project. PowerShell is also now available on Linux and macOS. Developers can download PowerShell open source project from GitHub. There are other alpha versions available for the Ubuntu, Centos, Red Hat variants of Linux and OS X 10.11.
Microsoft posted in official blog:
Now, users across Windows and Linux, current and new PowerShell users, even application developers can experience a rich interactive scripting language as well as a heterogeneous automation and configuration management that works well with your existing tools. Your PowerShell skills are now even more marketable, and your Windows and Linux teams, who may have had to work separately, can now work together more easily.