How @ became the most important item on the keyboard

Thanks to reader Reese, I learned that Ray Tomlinson had just died at the age of 74. Who was Tomlinson? He was the person who invented email. In 1971 he was working on ARPANET, the precursor to the internet, and fooling around trying to find more uses for it when he invented it.

Tomlinson once said in a company interview that he created email “mostly because it seemed like a neat idea”. The first email was sent between two machines that were side-by-side, according to that interview.

He said the test messages were “entirely forgettable and I have, therefore, forgotten them”. But when he was satisfied that the program seemed to work, he announced it via his own invention by sending a message to co-workers explaining how it could be used.

Tomlinson decided to use the @ symbol to demarcate the username from the destination because it seemed the least likely to occur normally as part of the address. I recall encountering and using the @ symbol only in my bookkeeping classes as part of an accountancy program, to denote the cost per unit of an item. If not for his adoption, that symbol may well have gone extinct because of its highly limited utility.

But that is of course a trivial aspect of Tomlinson’s work. Email has revolutionized communications and it is hard to imagine a world without it

I first encountered email before the general public because I was working for US universities and national laboratories and we used a system that existed between those institutions before the arrival of the internet. It was known as BITNET that stood for ‘Because It’s There Network’.


  1. Friendly says

    If not for his adoption, that symbol may well have gone extinct because of its highly limited utility.

    Most non-European languages have had to invent a name for that symbol because, until now, it was never used or encountered outside historically European cultural contexts.

  2. Andrew Dalke says

    Tomlinson did not invent email. See and others for examples of earlier email programs. Tomlinson worked on SNDMSG, which is “chiefly notable because it was used to send what is considered the first networked email” . Tomlinson decided to use the ‘@’ to indicate the remote computer.

    As for the “@” sign, Tomlinson chose it because he used a Model 33 teletype, which was one of the first machines to be based on the recently developed ASCII code, and it had an “@” key. In the 1960s there was much debate about which characters to have in the code. The “@” key was on typewriters of that era, as were ¢, ½, and ¼. Other options which might have been chosen were ≤, ≥, ±, √, and ° (see ). That paper points out that “@” was the “softest” of the characters, and “it was forecast that, in the French national variant of the ISO 7-Bit Code, @ would be replaced by à”, so it certainly was the least important of the chosen symbols. But it was still thought to be important enough to keep.

    I researched this a bit because in January I came across a 1965 letter from Herbert Gross of NCR to Calvin Mooers, regarding a letter Mooers had distributed as part of the ASCII standardization process. Gross wrote “The essential, and almost completely overlooked, point is that _no_ _one_ _uses_ “commercial-at” in commercial billing, or in any other data processing application. And moreover, no one _has_ _used_ that symbol on an invoice since the last time that Scrooge bought Bob Cratchitt a new quill pen.”

    Since then I’ve been trying to figure out why the committee members decided it would be more common in the future to write “I’ll buy 2 @ $5” than “It’s 15° outside.” I still don’t know. But surely they are no less important to saving the “@” key and letting ¢, ½, and ¼ die.

    Would the “@” still have gone extinct without Tomlinson? I don’t see how, and I don’t like how that thesis has been going around in the last week. It is part of standard ASCII, and was used for purposes other than email even before Tomlinson. (For example, there’s a “@” in Algol 68.) It’s used in diverse ways in many modern programming languages, and the Wikipedia page lists a few non-programming examples like “81 dB @ 80 km/h”. It feels somewhat like saying that ‘#’ -- described variously as hash, pound sign, octothorpe, and number sign -- was going extinct before the hashtag. For that matter, is ‘|’ going extinct?

  3. moarscienceplz says

    Since then I’ve been trying to figure out why the committee members decided it would be more common in the future to write “I’ll buy 2 @ $5” than “It’s 15° outside.” … But surely they are no less important to saving the “@” key and letting ¢, ½, and ¼ die.

    Personally, I never liked ½, and ¼. All other fractions have to be depicted some other way anyhow, so it’s just jarring to me to see “This drill bit set includes 1/8, ¼, 3/8, and ½ inch bits”.
    I do wish they had maintained °. I participate in an amateur chemistry discussion group, and it’s annoying to type “degC” all the time, and looking up the Ascii code for ° and entering it in directly is even worse.

    For that matter, is ‘|’ going extinct?

    C and C++ use | to indicate the Boolean ‘or’ function, I use it almost every day.

  4. Andrew Dalke says

    I too would have preferred ° over @ and do not morn the loss of ¢, ½, and ¼. It would also have let people write N°.

    I use @ almost every day. It’s a symbol for atomic chirality in one of the chemistry notations I work with. (“@” means clockwise chiral; “@@” means anti-clockwise.) I also use it in Python. These are examples of why “@” was not in fear of extinction but for email addresses.

    C did not need to use “|” for logical and bitwise or. ALGOL in the early 1960s used ∧ and ∨ for the boolean operators. Bob Bemer in 1961 proposed that “\” be part of ASCII so those operators could be written /\ and \/ in an ASCII version of ALGOL. There’s no reason C and its descendants couldn’t have done the same thing, at the cost of an extra few characters. In fact, that ASCII history I pointed to goes into the details of the lengthy debate on how to write ∧ and ∨ in ASCII, including a proposal for using ^ and !, and complaints about /\ and \/.

    If Tomlinson saved @ from extinction, then perhaps it’s reasonable to say that Ritchie helped save “|” from extinction? Or that Microsoft helped save the “\” key from extinction by using it as the directory separator instead of the “/” of Unix and CP/M?

  5. says

    I like @ because of the appropriateness of it. You are at such-and-such a place, both physically and electronically. Simple, yet effective. What’s the next debate going to be, the asterisk or pound sign (and whether we should keep them or their origins)?

    Friendly (#1) --

    It’s not native to all European countries either. Some have very colourful names for it (e.g. cinnamon bun in Sweden). The French call it the arobase which derives from the Spanish word for snail.

    Andrew Dalke (#4) --

    Would the “@” still have gone extinct without Tomlinson?

    It may well have. The ampersand (“&”) was a letter in the Latin alphabet since ancient Rome but only fell out of common use in the 19th century. Now it’s only a substitute for “and” in signs, not a word-letter unto itself.

  6. lanir says

    The info I got on email was long after the fact but it tended to focus on how it replaced UUCP as a method of sending messages. UUCP is no longer in use but if it were it would be much more obnoxious than email. If writing a letter to your mom at you’d instead have to know the full path including every server along the way. For a quick look at what that might look like, try opening a command prompt (Start -> Run -> Type “cmd” without the quotes and hit enter) and type in:


    Once you hit enter you’ll see a list of systems along the way. And it would change between home and work or mobile phone network.

  7. Andrew Dalke says

    While cinnamon bun, monkey tail, and others are more fanciful terms in Swedish, the recommended term is “snabel-a”. That’s what I’ve heard the most here in Sweden. The recommendation itself (in Swedish) is at . The use of kanelbulle in Swedish is akin to using ‘strudel’ in English, which a fanciful alternative name listed on the English Wikipedia page for @.

    I don’t think there’s a mechanism by which the “@” key on the keyboard would have gone extinct by this time without Tomlinson. Look at how long it’s taken for the F-keys to disappear, and those have even less meaning. I think that if a key exists, then some people will find a use for it (like C programmers), and complain about any change. And unlike typewriters, which only write to paper, ASCII is meant for information interchange. This locks in a bias towards given set of characters, which is why it took years of international meetings to decide which characters to use and how to represent them.

    I did not know that the & was once treated as a letter in the alphabet. Thank you.

  8. Dunc says

    The function keys are actually quite widely used for keyboard shortcuts -- I use them every day. Scroll lock, on the other hand, seems to be entirely useless.

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