Lisp is programmable programming language, especially Common Lisp. It works as programmer amplifier. Better you are, more you benefit from it.

I challenge anyone to watch this lecture from Christian Schafmeister and say they are not impressed: https://www.youtube.com/watch?v=8X69_42Mj-g and https://www.youtube.com/watch?v=0rSMt1pAlbE

What popular programs are written in Lisp?

I'm regularly hearing about web applications written in ClojureScript, a.k.a. Clojure (a dialect of Lisp, [1]) compiled to JavaScript. Recently I've heard of:

- https://github.com/asciinema/asciinema-player

- https://precursorapp.com/ (not open-source)

[1] http://www.clojure.org/