{{stub}}{{language}} TECO stands for Text Editor and COrrector. (Originally "Tape Editor and COrrector"). Macro language for text editing, screen handling and keyboard management. Has a reputation for being cryptic and hard to learn. (TECO programs are said to resemble line noise.) TECO was an early, string-processing language used by the first Emacs. It made maintenance hard, and also made extensions hard to write. The first EMACS editor was written in TECO.