FISH – A smart and user-friendly command line shell for Linux
fish suggests commands as you type based on history and completions, just like a web browser. Watch out, Netscape Navigator 4.0!
Glorious VGA Color
fish natively supports term256, the state of the art in terminal technology. You'll have an astonishing 256 colors available for use!
fish is fully scriptable, and its syntax is simple, clean, and consistent. You'll never write esac again.
Web Based configuration
For those lucky few with a graphical computer, you can set your colors and view functions, variables, and history all from a web page.
Man Page Completions
Other shells support programmable completions, but only fish generates them automatically by parsing your installed man pages.
Works Out Of The Box
fish will delight you with features like tab completions and syntax highlighting that just work, with nothing new to learn or configure.
Install FISH On ubuntu 15.04
Open the terminal and run the following commands
sudo apt-add-repository ppa:fish-shell/release-2
sudo apt-get update
sudo apt-get install fish
Open the terminal and run the following command to start FISH
Welcome to fish, the friendly interactive shell
Type help for instructions on how to use fish
Check FISH Documentation How to use.