Add support for multiple languages to your Unity projects by storing strings with multiple translations in one or more XML files and referencing those strings with a common string identifier. If you're familiar with adding support for multiple languages with Android then you already have a good idea of how UMLS works. Unlike Android's implementation UMLS allows you to divy up the language XML files however you like rather than having to use one XML file per language.
UMLS includes support for both standalone and web-player builds and comes packed with documentation to help get you started adding languages to your projects.