:- turns 20

It was 20 years ago today that Scott Fahlman taught the Net how to smile. The IBM researcher has devoted his professional life to artificial intelligence, the practice of teaching computers how to think human.

On Sept. 19, 1982, Fahlman typed :- in an online message. The 8216;8216;smiley face8217;8217; has since become a staple of online communication, allowing 12-year-olds and corporate lawyers alike to punctuate their messages with a quick symbol that says, 8216;8216;hey, I8217;m only joking.8217;8217;

In the 8217;80s, users of a Carnegie Mellon University bulletin board proposed a variety of markers for humourous comments, like , , 038;, and 8212;8212;/. Fahlman suggested :-, along with the admonition to 8216;8216;read it sideways.8217;8217; Before long, other bulletin board users were placing the smiley face in their messages.