org-export-backends

org-export-backends is a variable defined in `org.el'.
Its value is

(ascii html icalendar latex)

Documentation:
List of export back-ends that should be always available.

If a description starts with , the file is not part of Emacs
and loading it will require that you have downloaded and properly
installed the Org mode distribution.

Unlike to `org-modules', libraries in this list will not be
loaded along with Org, but only once the export framework is
needed.

This variable needs to be set before org.el is loaded. If you
need to make a change while Emacs is running, use the customize
interface or run the following code, where VAL stands for the new
value of the variable, after updating it:

(progn
(setq org-export--registered-backends
(org-remove-if-not
(lambda (backend)
(let ((name (org-export-backend-name backend)))
(or (memq name val)
(catch 'parentp
(dolist (b val)
(and (org-export-derived-backend-p b name)
(throw 'parentp t)))))))
org-export--registered-backends))
(let ((new-list (mapcar 'org-export-backend-name
org-export--registered-backends)))
(dolist (backend val)
(cond
((not (load (format "ox-%s" backend) t t))
(message "Problems while trying to load export back-end `%s'"
backend))
((not (memq backend new-list)) (push backend new-list))))
(set-default 'org-export-backends new-list)))

Adding a back-end to this list will also pull the back-end it
depends on, if any.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.4 of Emacs.