GNU Emacs

GNU Emacs is a text editor and suite of free software tools. Its development began in 1984 by GNU Project founder Richard Stallman, based on the Emacs editor developed for Unix operating systems. GNU Emacs has been a central component of the GNU project and a flagship project of the free software movement. The program's tagline is "the extensible self-documenting text editor." Most functionality in GNU Emacs is implemented in user-accessible Emacs Lisp, allowing deep extensibility directly by users and through community-contributed packages. Its built-in features include a file browser and editor (Dired), an advanced calculator (Calc), an email client and news reader (Gnus), a Language Server Protocol integration, and the productivity system Org-mode. A large community of users have contributed extensions such as the Git interface Magit, the Vim emulation layer Evil, several search frameworks, the window manager EXWM, and tools for working with a wide range of programming languages.