Teco

Digital Equipment Corporation created TECO (Text Editor and Corrector) in the 1960s, using nearly every character in the ASCII character set as a command. This was not user-friendly, as any attempt to enter text might turn into a command.

TECO also had a powerful macro facility, including the ability to manipulate registers and the program counter directly, leading to some of the most amazing "editing" ever seen. The reference manual included as an example a pretty-print routine for assembly language programs. One version in the 1970s was one of the first video-oriented editors. Most editors up to that time had been line-oriented.

The first version of Emacs was implemented as a set of TECO macros.

See: text editor, Digital Equipment Corporation