The TECO character-oriented text editor, famous for its powerful but arcane editing and programming language, was ported to Multics by Rick Gumpertz and Mike Grady. TECO's steep learning curve makes it unsuitable for casual users, but its command set's low dependence on control characters and non-alphanumeric characters makes it easier to use on terminals with simplified keyboards like tablets and smartphones.

Although Multics TECO is based on the PDP-10 version of the editor there are some minor variations in the command set.

The following 4 rules and 12 commands are enough for useful basic editing of text files on Multics with TECO.

1. Invoke TECO with the command teco filename.
2. Commands typed into TECO are executed by pressing the dollar-sign ($) followed by the Enter key.
3. Commands don't have to be executed one-at-a-time. You can type a long series of commands followed by $ Enter and TECO will execute the commands in order.
4. TECO is character-oriented, so it remembers the character position of your current location in the file, called “pointer”. Most commands display or change the file's contents at pointer, or move pointer to another location in the file.

The TECO command prompt is Z. TECO commands are case-insensitive.

[1] May insert numeric prefix to move/delete multiple characters (negative reverses direction)
[2] May insert numeric prefix to move/type/delete multiple lines (negative reverses direction); (T, K only) prefix H: type/delete whole file
[3] Any character not included in text may be substituted for the delimiters : above

For more information, try the help teco command or see the TECO section in Multics System Tools Program Logic Manual.