@ appears to be the cursive form of ā, an abbreviation of an unknown word beginning with a. In medieval European manuscripts, abbreviations were generally indicated by drawing a line over or through the letters, as in the common IX for Jesus Christ, or # from lb for libra 'pound'. In the typeface of the Gutenberg Bible, ā stands for either an or am within words. However, it is not known which par ...
The symbol's most familiar modern use is in e-mail addresses (sent by SMTP), as in jdoe@example.com ("the user named ‘jdoe’ working at the computer named ‘example’ in the ‘com’ domain"). Ray Tomlinson is credited with the introduction of this use in 1972. This idea of user@host is seen in many other tools and protocols as well: for example, the command ssh jdoe@www.example.com would try to establish a ssh connection to the box with the hostname w ...
