I've recently written an extension[1] which allows to easily inject custom tabs into the standard Subject-Talk scheme (with some fancy toys like tabs re-arranging). This is the feature that is currently implemented on some Wikinews and Wiktionary projects via JavaScript.

Prior discussion took place at Bugzilla and evolved into the RfC[2] (look for Bugzilla link there). The coding is quite done (see [1]), but one change is on review in Gerrit[3] (introduces same namespace tabs for Wiktionary + code redesign); it lacks attention so it hasn't been merged yet. People at Wikinews and Wiktionary are commonly not against the new extension.[5][6]

I sent an e-mail to Howie Fung, as it is suggested in "Writing an extension for deployment" manual on MediaWiki.org,[4] but I haven't received any response yet.

I don't know what should I add here, so please could you take care of it? I'll be glad to answer your questions!

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[1] https://www.mediawiki.org/wiki/Extension:NamespaceRelations

[2] https://www.mediawiki.org/wiki/Requests_for_comment/Custom_inter-namespace_tabs

[3] https://gerrit.wikimedia.org/r/#/c/44335/

[4] http://www.mediawiki.org/wiki/Writing_an_extension_for_deployment

[5] http://en.wikinews.org/wiki/Wikinews:Water_cooler/technical#Opinions_tab:_extension_vs._MediaWiki:Comments.js

[6] http://en.wiktionary.org/wiki/Wiktionary:Grease_pit/2013/January#Citations_tab:_extension_vs._citations_tab.28.29
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