Use the adjective obsolete for something that is out of date. As the Rolling Stones song "Out of Time" goes, "You're obsolete, my baby, my poor old-fashioned baby."
Obsolete is from the Latin obsolescere "to fall into disuse," and it is a very handy adjective for anything that is no longer used, from words to factories to computer software to ways of thinking. Something that is obsolete has usually been displaced by a newer, shinier innovation. Compact discs made records and cassettes obsolete, and then downloadable digital music files made compact discs obsolete.
