Fish Shell

Fish, short for the friendly interactive shell, is a cross-platform command-line shell originally created by Axel Liljencrantz and rewritten in Rust starting with version 4.0.0 released in February 2025, with the current version being 4.7.1 as of May 2026. The shell is designed to be user-friendly and feature-rich out of the box, requiring no additional configuration or plugin installation to access its core capabilities. Tab completion works automatically by parsing man pages and command help output, generating context-aware completions for file paths, options, and arguments without manual completion scripts. Syntax highlighting renders commands in real time, coloring valid commands green, errors red, options cyan, strings yellow, and valid paths with underlines, giving immediate visual feedback before pressing Enter. Autosuggestion analyzes command history, file completions, and valid commands to suggest the most likely next characters as the user types, accepted with the right arrow key or Control+F, similar to web browser address bar suggestions. Abbreviations allow short trigger words to expand into full commands on execution, providing the speed of aliases with the readability of complete commands in history. Fish supports 24-bit true color for terminal rendering and provides a web-based configuration interface accessible through the fish_config command, where users can select prompt themes, configure colors, browse functions, inspect variables, and view command history in a browser. The scripting language uses a clean syntax with switch and case statements instead of case and esac, and if and end blocks instead of then and fi. The project is open source on GitHub under the GPL license with community support through Matrix, mailing lists, and Stack Exchange.