User blog comment:Grunny/Introducing Lua, for faster and more powerful templates/@comment-24901466-20140611164333/@comment-4522253-20140611170059

It's not a Wikia specific language. It's an alternate language for wikitext templates that's used on most Wikis, including Wikipedia (where it's been commonplace for years). It doesn't replace simple Wikitext, and it's only for Templates. If you don't create templates, this is a total non-issue for you. If you do make Templates, you still don't NEED to use it. But if you make complex templates, you may WANT to learn it.