Thread:Sannse/@comment-10756680-20130905124017/@comment-4712589-20130905171004

I think reference popups on developers wiki is the feature you're thinking of. Just put the following code in your MediaWiki:Wikia.js

importArticles({   type: 'script',    articles: [        // ...        'w:c:dev:ReferencePopups/code.js',        // ...    ] });