Emacs
Emacs is a family of extensible text editors, best known through GNU Emacs. Users can customize its commands, modes, and interface with Lisp programs.
Emacs Lisp: Emacs Lisp is the programming language used to extend and customize GNU Emacs. It supplies the language for defining commands, changing behavior, and building extensions.
TECO: TECO is an early text editor and programming language developed at MIT in the 1960s. Emacs began as a set of macros that made TECO more convenient to use.
Org mode: Org mode is an Emacs major mode for outlining, task management, literate programming, and document authoring. It turns Emacs into an environment for organizing projects and producing structured documents.
Vim: Vim is a modal text editor derived from the vi editor, with commands organized around modes of interaction. Vim offers a contrasting keyboard-centered approach without Emacs's pervasive Lisp extension model.
Major mode: A major mode configures an editor for a particular kind of text or activity. Major modes give Emacs distinct editing behavior for languages, documents, and other tasks.
Richard Stallman: Richard Stallman is an American programmer who founded the GNU Project and wrote the original GNU Emacs. He began GNU Emacs in 1984 as part of the GNU operating-system project.
ESS: Emacs Speaks Statistics is an Emacs package for editing and interacting with statistical programming languages. ESS adapts Emacs for statistical work with languages such as R and SAS.
GNU nano: GNU nano is a small, beginner-oriented command-line text editor with visible keyboard shortcuts. Nano favors immediate simplicity over Emacs's extensive customization and command environment.
Minor mode: A minor mode adds or alters an editor feature without replacing its main editing mode. Minor modes let Emacs layer optional features onto a major mode.
James Gosling: James Gosling is a Canadian computer scientist who created Gosling Emacs, an early extensible editor. His editor influenced GNU Emacs and helped establish the Emacs name.