‘fol dingo’ means in French “crazy mad” 
This package was inspired by outline mode, folding.el (from Jamie Lokier), tinyfold.el (Jari Aalto), foldout.el (Kevin Broadey). Advantages with respect to other packages:
Keybindings are:
You cannot get a copy here because this link is broken http://youpou.lip6.fr/queinnec/Miscellaneous/foldingo.el
…this one doesn’t work either: http://www-spi.lip6.fr/~queinnec/Miscellaneous/foldingo.el
…but this one works: http://pagesperso-systeme.lip6.fr/Christian.Queinnec/Miscellaneous/foldingo.el
For TeX users: I made my “tex-mode.el” override the keybindings for C-c f i and C-c f c with the according definitions for TeX. This way I usually got C(++) foldings and TeX foldings when in (La)TeX mode accessible via the keyboard.
Here is what you got to do if you want the same:
At the LaTeX keymap definition (in file “tex-mode.el”)
(defun tex-define-common-keys(keymap)...
you insert the following two lines:
(define-key keymap "\C-cfi" 'insert-new-latex-fold)
(define-key keymap "\C-cfc" 'close-latex-fold)
then you append the following to the “tex-mode.el” (I put it just before the (run hooks…) statement:
(defun close-latex-fold ()
"Closing a fold for LaTeX."
(interactive "*")
(if (not (bolp))
(insert ?\n))
(insert "%%}}}%%\n")
)
(defun insert-new-latex-fold (foldname)
"Insert a new fold for LaTeX."
(interactive "*sTitle of the new fold: ")
(if (not (bolp))
(insert ?\n))
(insert (format "%%%%{{{ %s %%%%\n"
foldname))
)
Now you byte-compile the “tex-mode.el” again and everything should work fine.
Quand le source dit : “Caution: this hook must be appended and not prepended since fold-mode uses ^M characters and these characters may trigger some other hooks”, il faut comprendre quoi ?
append, c’est mettre devant, mais devant quoi ? (When the source says “Caution…”, what am I supposed to understand ?
append means put before, but, before what ?). If a put this question here, it’s ‘cause I think I might not be the only one not to understand (at least I hope so !) – LucasBonnet
Such text usually refers to wether things get appended to the front or the end of a list. See ListModification. – AlexSchroeder
Is foldingo dead? The above link points to a version that is about four years old. Is folding the better way to go? – DavidMasterson