I don't mean to be boring, but Emacs has had a window manager for years, EXWM. Oh, and a browser, EWW. If you want Inception-level recursion, a virtual LISP machine is your friend.

Reminds me of my website from 2006 (not entirely reproduced) at https://web.archive.org/web/20060208131821/http://www.pixelb...