Here are John McCarthy's own answers to this question, from 1980, about 20 years after he invented Lisp: The Survival of LISP http://www-formal.stanford.edu/jm

Here are John McCarthy's own answers to this question, from 1980, about 20 years after he invented Lisp: The Survival of LISP http://www-formal.stanford.edu/jmc/lisp20th/node2.html http://www-formal.stanford.edu/jmc/lisp20th/node2.html He describes 15 innovations -- it is impressive that these were all innovations when he invented Lisp. He adds, "Of course, the above doesn't mention features that LISP has in common with most programming languages".