What are some alternatives?
When comparing zsh and KornShell, you can also consider the following products
fish - The friendly interactive shell.
DASH - DASH is a secure, blockchain-based global financial network which offers private transactions.
GNU Bourne Again SHell - Bash is the shell, or command language interpreter, that will appear in the GNU operating system.
Xiki - Xiki makes the command line friendlier and more powerful.
fshell - fshell is the Symbian equivalent of bash + telnet + a posix-like set of command-line tools.
the xonsh shell - Xonsh is a Python-powered, cross-platform, Unix-gazing shell language and command prompt.