It's very different but quite interesting.
While the *nix shells work with text & files, PowerShell works with
objects instead. This can be quite useful when extracting information, for example to get the memory usage for my GNOME shell I can run
Code:
PS /home/empty> Get-Process -name gnome-shell | % { $_.WS/1MB }
211.19140625
PS /home/empty>
It's not particularly lightweight though:
Code:
736.0 KiB + 43.5 KiB = 779.5 KiB mksh
129.2 MiB + 1.8 MiB = 130.9 MiB pwsh
And in respect of the origin it's difficult to criticise MS too much any more given that they are a Platinum Member of the Linux Foundation
[0] and they have been classified as either Silver or Gold sponsors for the OpenBSD Foundation since 2015
[1].
There seems to be a FreeBSD port in progress:
https://reviews.freebsd.org/D16707