High Quality Content by WIKIPEDIA articles! The friendly interactive shell (fish) is a Unix shell that focuses on interactive use, discoverability, and user friendliness. The design goal of fish is to give the user a rich set of powerful features in a way that is easy to discover, remember, and use. Released in 2005 under the terms of the GNU General Public License, fish is free software. Fish features a user-friendly and powerful tab-completion, including descriptions of every completion, tab-completion of strings with wildcards, and many command specific completions. It also features an extensive and discoverable help system. A special help command gives access to all the fish documentation in the user's web browser.