This is PowerShell Core only, Alpha Version 18.104.22.168 and there’s a lot of work to do. Bugs and feedback are been submitted as the community are contributing for it success.
This version is also available for Windows 10 / Server 2016 and Windows 8.1 / Server 2012 R2. You can have it side-by-side with the current version of PowerShell.
Max has notes on how to install it on Ubuntu. Given that Microsoft is bringing Bash to Windows and Powershell to Linux, these are interesting times.