hello,
I have published recently the extension PageProperties
it is mainly a page properties aggregator where users can
set display title, language and content model of a page, in one place,
plus defining SEO meta data and
Semantic Mediawiki properties (provided that SMW is installed)
without annotating them manually on the page.
It partly develops the concept of "Enterprise Mediawiki" mentioned here
(together with other extensions which are either in beta status, or not yet
published that I plan to publish progressively.)
Technically, it uses the Javascript tabs used by PreferencesFormOOUI,
plus other pieces taken from the DisplayTitle extension (mentioned within
the code) and from the special pages SpecialPageLanguage and
SpecialChangeContentModel, and of course original code.
Kind regards
(Thomas)