Thread:Extension talk:Scribunto/Adding external libraries/packages?/reply

A pure-Lua library can be placed in a Module page and loaded from other modules. But be sure that you are not violating the license of the library by doing so.

For libraries or packages with a native-code (e.g. C) component, it's not likely. The closest you can easily come here is to write it partially in PHP and add it via a MediaWiki extension, as documented at Extension:Scribunto/Lua reference manual.