lisp programs are used in the industry mostly. everything which is bit more complicated, and is happy with a one-man dev team. extremely cool apps. open source I only know gmane and sawfish. emacs and autolisp certainly not, these are atrocious dialects.

Famous are schedulers or AI apps, such Orbitz and DART. http://www.paulgraham.com/carl.html

https://stackoverflow.com/questions/543579/what-is-the-most-... and http://franz.com/success/ have lists.