Extension:ShoutWiki Interwiki Magic

The ShoutWiki Interwiki Magic fetches interwiki links (as opposed to interlanguage links) from $wgSharedDB while still fetching interlanguge links from the local database.

This way it is possible to have a list of global interwiki links (which are stored in $wgSharedDB's interwiki table) without adding the interwiki table to $wgSharedTables.

This extension was written by Jack Phoenix for ShoutWiki to replace the old core hack ShoutWiki had in includes/Interwiki.php; this extension thus effectively fixes ShoutWiki bug #12 (but Extension:SpecialInterwiki still needs to be patched - see ShoutWiki/Patches/Interwiki).