Paul Graham May 2003 "why don't more people use it? I was asked this question by a student in the audience at a talk I gave recently. Not for the first time, either."
Paul Graham May 2001 "You don't need to know this stuff to program in Lisp, but it should be helpful to anyone who wants to understand the essence of Lisp"
"...Norvig had written the program in Lisp in 2 hours, while the times for the C++ developers ranged from 3 to 25 hours." After I read that, I knew I had to try the problem.
Guy Steele's keynote at the 1998 ACM OOPSLA conference on "Growing a Language" (mostly about JAVA) discusses the importance of and issues associated with designing a programming language that can be grown by its users.