Why should I learn Lisp? | I really feel that I should learn [Lisp](http://en.wikipedia.org/wiki/Lisp_(programming_language)) and there are plenty of good resources out there to help me do it.


I'm not put off by the complicated syntax, but where in "traditional commercial programming" would I find places it would make sense to use it instead of a procedural language.


Is there a commercial killer-app out there that's been written in Lisp ?