What are some alternatives?
When comparing Rush and Nu Shell, you can also consider the following products
zsh - The Z shell (Zsh) is a Unix shell that can be used as an interactive login shell and as a powerful command interpreter for shell scripting.
fish - The friendly interactive shell.
DASH - DASH is a secure, blockchain-based global financial network which offers private transactions.
PowerShell - Download WMF. Windows Management Framework contains the latest versions of PowerShell, DSC, WMI, and WinRM for older versions of Windows. PowerShell Module Browser. Search for PowerShell modules and cmdlets.
rc - a shell - This is a reimplementation for Unix, by Byron Rakitzis, of the Plan 9 shell.
the xonsh shell - Xonsh is a Python-powered, cross-platform, Unix-gazing shell language and command prompt.