03/12/2016 - LINUX, MAC
At the end of the command below, it might say ".... doesn't exist" but you can ignore it.
$ sudo apt-get install zsh
$ sh -c "$(curl -fsSL https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)"
Please look over the ~/.zshrc file to select plugins, themes, and options.
ZSH_THEME="robbyrussell" and change it with the theme you like.
$ sudo nano ~/.zshrc
If you want to switch between "bash" and "zsh" shells, all you have to do is type either
$ bash or
$ zsh or