Dang, it's been a while since I've used Ratpoison. I'm on EXWM now, but I really enjoyed using StumpWM, which is a spiritual successor to Ratpoison, and it's written in Lisp.
It's amazing to see the development of tiling ideas on X11. Ratpoison, sure. wmii, dwm, i3, scrotwm....<p>Now it seems like we mostly have settled on i3, I do sometimes miss autotiling, scrotwm specifically, but I do like that we sort of 'solved' tiling.