Wikia has had this functionality for Lua for several months, although it is likely not used as much as it would be in wikipedia or other similar farms / wikis. The system seems to work reasonably well. Basically, all modules can either be hosted locally in a particular wiki or in dev.wikia.com and must be explicitly loaded using a syntax like "require ("Dev:Arguments")". This fetches modules from dev.wikia and uses them in a different wiki, e.g. templates.wikia.com. It also allows a mix of local and foreign modules, so if a script from the central repository doesn't explictly use the Dev:Arguments syntax, it tries to fetch the module locally.