(Text Editor and COrrector) A text editor written in 1963 by Dan Murphy at MIT for editing paper tape on a Digital PDP-1 computer (it was originally called "Tape Editor and Corrector"). Seeming primeval compared to today's editors, TECO worked on only one page at a time using cryptic one and two-character commands. A macro capability was added to TECO by Richard Stallman, creating the first Emacs editor, which he later rewrote for the GNU Project. See Emacs and TOPS.