“...StumpWM grew out of the authors’ frustration with writing ratpoison in C. Very quickly we realized we were building into ratpoison lispy-emacs style paradigms. We had a REPL hanging off ‘C-t :’, hooks, and a growing subset of Common Lisp in the implementation … It was clear what we really wanted was a window manager written in Lisp from the ground up with lots of room for customizing and real-time hacking.” --
* I can't watch the video :( Can you post it in ogg format next time ?