http://en.wikipedia.org/wiki/Internationalization_and_localization
In an i18n’d application all sentences and words that the user can see are in a separate file dynamically loaded depending on the locale used by the user. In other words if you add a Swedish translation file to it.. It starts showing in Swedish in your Swedish environment.. Automatically
The translatable items and the program logic are separated so that anybody can easily translate the application.
All mint tools are going through this at the moment. MintUpdate and mintInstall are already i18n, mintDesktop is getting i18n’d as we speak.
Launchpad will coordinate translation efforts for these projects.
When will it be possible to help to translate the applications? It isn’t possible right now.