Scott Elliott Fahlman (born March 21, 1948) is a computer scientist at Carnegie Mellon University.
Fahlman is notable for early work on automated planning in a blocks world, on semantic networks, on neural networks (and, in particular, the cascade correlation algorithm), on the Dylan programming language, and on Common Lisp (in particular CMU Common Lisp and he was one of the founders of Lucid Inc.). During the period when it was standardized, he was recognized as “the leader of Common Lisp.”
Fahlman is credited with originating the first smiley emoticon, which he thought would help people on a message board at Carnegie Mellon to distinguish serious posts from jokes. He proposed the use of 🙂 and 🙁 for this purpose, and the symbols caught on. The original message from which these symbols originated was posted on September 19, 1982. The message was recovered by Jeff Baird on September 10, 2002 and is quoted:
19-Sep-82 11:44 Scott E Fahlman :-) From: Scott E Fahlman <Fahlman at Cmu-20c> I propose that the following character sequence for joke markers: :-) Read it sideways. Actually, it is probably more economical to mark things that are NOT jokes, given current trends. For this, use :-(