Isn't there some way to use standard wikitext to achieve the same
rendered result as
$ GET
http://abj.jidanni.org/index.php?title=MediaWiki:Sidebar&action=raw
* navigation
** mainpage|mainpage-description
** Special:NewPages|newpages
** Special:Categories|categories
** recentchanges-url|recentchanges
** randompage-url|randompage
* SEARCH
* TOOLBOX
* LANGUAGES
That way there would be no need to maintain a separate "sidebar
language" interpreter.