Experimente os arquivos de backup do gnu emacs
GNU Emacs
;; Put autosave files (ie #foo#) in one place, *not*
;; scattered all over the file system!
(defvar autosave-dir
(concat "/tmp/emacs_autosaves/" (user-login-name) "/"))
(make-directory autosave-dir t)
(defun auto-save-file-name-p (filename)
(string-match "^#.*#$" (file-name-nondirectory filename)))
(defun make-auto-save-file-name ()
(concat autosave-dir
(if buffer-file-name
(concat "#" (file-name-nondirectory buffer-file-name) "#")
(expand-file-name
(concat "#%" (buffer-name) "#")))))
;; Put backup files (ie foo~) in one place too. (The backup-directory-alist
;; list contains regexp=>directory mappings; filenames matching a regexp are
;; backed up in the corresponding directory. Emacs will mkdir it if necessary.)
(defvar backup-dir (concat "/tmp/emacs_backups/" (user-login-name) "/"))
(setq backup-directory-alist (list (cons "." backup-dir)))
Uma versão para XEmacs pode ser encontrada se você seguir o link no topo desta resposta.