User blog comment:Kirkburn/Technical Update: June 24, 2015/@comment--20150626151657/@comment-126761-20150626152025

It means that Lua modules can be stored on the Dev wiki, then easily utilised around the site. It's similar to how some custom JS features are used - the code is stored in one central place, which users can then use all around the site. It means you can make tweaks and improvements to the Lua template setup on multiple communities while only editing one page.