Board Thread:Support Requests - Getting Technical/@comment-4522253-20130415032116/@comment-3335785-20130415201054

This is the only example of anyone writing an extension for use on a Wikia wiki that isn't someone who works at Wikia I know of. There might be some LyricWiki specific extensions written by someone from that wiki, but I wouldn't be surprised if they were developed by Wikia.

The author of the linked page is long since inactive, but it looks like they used Special:Contact to get the source updated as needed. Wikia don't tend to update extensions until MediaWiki upgrades from what I've been told before, so that's probably the only way.