So basically you're proposing to make a centralized project simply for the creation and maintaining of interwiki links?

While the interwiki system isn't ideal, I don't see this method as being feasible.

chuck wrote:

For an implementation, see: http://meta.wikimedia.org/wiki/Multilingual_MediaWiki
It's feasible, but slow.

updated summary.

conrad.irwin wrote:

This would be much easier to implement for Wiktionary, if someone wants to go for the "first step" (while getting the interwikis from the database to the page-rendering is the same for both, Wiktionary interwiki links are always to the identical title and so maintaining the database is trivial) - though at the moment [[wikt:User:Interwicket]] is able to cope with all of the interwikis there so there's no pressure to do so. (I had a very early prototype last summer that kept the interwiki table up-to-date by monitoring IRC, though that approach won't work for the Wikipedia system).

See also related bug 239.

And also bug 15607.

mbalazs17 wrote:

Necessary in order to add interwikis to not yet existing articles and making sure at the same time that the correct title is linked. Very important in the case of small Wikis, where important articles are missing. It helps the reader change language.

Adjusting summary to avoid confusion in bug 29673 comment 2 and 3

This would now be a duplicate of bug 44515, if only that wasn't exclusively about about Wikipedias. Moving to Wikidata component nevertheless.
https://wikidata.org/w/index.php?title=Wikidata:Contact_the_development_team&oldid=9792169#Interwikis_on_Wiktionary_etc.

Wikidata now functions as a central database for interwiki links for Wikipedia and Wikivoyage. Should this bug be marked as fixed, or does that need to wait until all Wikimedia projects are supported by Wikidata?

I'm going to be bold and mark this as fixed. No need to keep this around to clutter the bugtracker. Wikidata is well on its way to supporting the remaining projects as well.