An escape sequence is a series of characters used to change the state of computers and their attached peripheral devices. These are also known as control sequences, reflecting their use in device control. Some control sequences are special characters that always have the same meaning. Escape sequences use an escape character to change the meaning of the characters which follow it, meaning that the characters can be interpreted as a command to be executed rather than as data.

Escape sequences are commonly used when a computer and a peripheral have only a single channel through which to send information back and forth. If the device in question is "dumb" and can only do one thing with the information being sent to it (for instance, print it) then there is no need for an escape sequence. However most devices have more than one capability, and thus need some way to distinguish information that is to be treated as data from information that is to be treated as commands.

An escape character is usually assigned to the Esc key on a computer keyboard, and can be sent in other ways than as part of an escape sequence. For example, the Esc key may be used as an input character in editors such as EMACS, or for backing up one level in a menu in some applications. The Hewlett Packard HP 2640 terminals had a key for a "display functions" mode which would display graphics for all control characters, including Esc, to aid in debugging applications.

Christian Wirth (born in the 1970s), better known by the pseudonym RaD Man, is an American computer artist and historian. He works in the field of ANSI art, a method of creating art using a limited set of text characters and color escape codes based loosely on the relevant ANSI standard (X3.64: Control Sequences for Video Terminals and Peripherals).

RaD Man was initially involved in the Aces of ANSI Art (AAA), an organization which created ANSI artwork for a number of computer bulletin board systems in the late 1980s. With others, he created the "ANSI Creators in Demand" group (also known as ACiD).

Starting in 1990, ACiD released artwork on an ad-hoc network of BBSes, updating a collection of art known as the ACiD Acquisition by sending a compressed file of all the completed work up to that time. By 1992, the increasing file size made this process impractical, and this led to the development of the artpack, where groups of artists (including ACiD) would upload monthly update packages instead.