Get-Help Get-Command -ShowWindow
I know this feature might not work but wanted to be reported,
Popup window with topic or command documentation
Nothing shows up.
Ubuntu 16.04 - powershell_6.0.0-alpha.8-1_amd64-ubuntu.16.04-x64

> $PSVersionTable
See this on my Macbook as well
By the way! This also applies to Windows PowerShell 6.0.0.9.
:)
Still seeing this on Alpha 18. It launches less without actually displaying any content. @SteveL-MSFT
-showwindow relies on WPF which isn't supported. -online is "equivalent" for now. Seems like maybe we should remove that switch. In 6.1.0 timeframe, I'd like to support curses and have interactive help at the console (searching, clickable links, etc...)
Just an FYI
Since I posted this feedback and I understand that can't be done yet, I'm started to play with Python 'tk' library to build the GUI apps. It seems to me like it's an opportunity to use Python in this case. Although I'm not a Python programmer I have figured out a raw sample for displaying results in a limited DataGrid-type view then integrate Python with PowerShell.
This is something to looked at! I think. And, I know it's going to take time to get it done.
:)

@MaximoTrinidad Brilliant idea!!
There's also the work being done in https://github.com/PowerShell/Phosphor that's trying to do this with HTML/CSS. Either way, pushing this out as a lower-priority.
Which file format will we use for Help? I see PowerShell-Docs use .md files.
Like for the Get-Help help system? We plan to continue using MAML/XML there for the short-term--PowerShell-Docs uses platyPS to convert our Markdown help to MAML before publishing it--but in the long-term we have a desire to natively support Markdown (but no timeline, it's just a dream we've been discussing for...two years? /cc @vors)
It would be wonderful to open up a Meta-Issue with Plan to add natively support for Markdown help that the desire becomes a reality faster.
@adityapatwardhan has been investigating the native markdown support and will eventually publish a RFC, we should probably just open an issue now to let people know you're working on this