ETAOIN SHRDLU

The Linotype (“line of type”) was a typesetting machine for setting metal “hot type” letters for a printing press. Each keystroke injected molten metal into a mold and the Linotype would produce an entire line of metal type at a time in a single metal ingot. 

The Linotype letters were arranged in order of frequency of use in the English alphabet, and so ETAOIN SHRDLU were the letters of the first two vertical columns on the left side of the keyboard and approximate the most common letters in English from most common to the left “E” and less common to the right “U.” 

This should be compared to the QWERTY typing standard in English keyboards, which was purposely designed with some of the least common letters on the primary row in order to slow typists down to keep them from typing so fast that they jammed the keys of the first mechanical typewriters. 

Etaoin Shrdlu was the title of a short story by Fredric Brown about a sentient Linotype machine of the same name. 

SHRDLU was the name of an artificial intelligence program developed in 1972 in the programming language LISP. (Thanks to Tony Schneider for this information.) 

The last issue of the New York Times composed using the Linotype machine appeared in July of 1978, and the typesetting of that last issue was captured in the documentary film Farewell Etaoin Shrdlu.


Schrödinger's Killer App: Race to Build the World's First Quantum Computer (Page 127). Taylor and Francis CRC 2013.

Linotype machine Model 6, built in 1965 (Deutsches Museum), with major components labeled. 

The notion that a sentient Linotype machine was at work, came about from a curious design flaw in the machine. As the typesetter typed away, there was no back or delete button. If you made a typo, your only choice was to start that entire single bar of type over again. To do this quickly, the typesetter would just type ETAIONSRDLU over and over again, because that was the easiest thing to type quickly and eject the flawed line of type into the recycling bin where it would be melted down again for reuse. But occasionally the typesetter would hit the send-to-print button instead of the send-to-recycling button. If that was missed by the editor, you would find "ETAONSRDLU" mysteriously in the middle of an article in the New York Times. These ghostly appearances gave rise to the rumor that a sentient gremlin by that name infested the printers at the NYT. Here is a famous example of such a typo from 1903.

An October 30, 1903 article from The New York Times containing the linotype string w:etaoin shrdlu.