Scott Fahlman

Scott Fahlman is an American computer scientist and professor emeritus at Carnegie Mellon University, known for early work on semantic networks, systems for representing real world knowledge as networks of linked concepts, described in his NETL thesis. He later developed the cascade correlation algorithm for training neural networks and helped lead standardization efforts for Common Lisp. Fahlman is also widely credited with originating the first emoticon, a sideways smiling face built from a colon, hyphen and closing parenthesis, proposed on a Carnegie Mellon computer science bulletin board on September 19, 1982, to mark posts intended as jokes.