From MegaZine3

This page lists all currently existing localizations for version 2.0 and newer. Note that the English and German localization files are also included in the releases and the SVN repository, as they are maintained by the developer. The English one is listed here nonetheless, to make it easier to get a base version for creating new localizations.

When adding new translations, please stick to the existing format (in the localization XML files as well as in this page). Please also take note that all localizations have to go to the correct subfolder in the set languages folder, being named as the ISO 639-1 id of the language.

When developing a custom plugin which needs localized strings, please do not modify the existing packs but post the localization separately. Create a new section on this page for that purpose. Thank you!

[edit] Core and Official Plugins

For those who wish to create a new translation, the most up-to-date versions of the single files can be found in the SVN repository. If you are better in German than in English, consider basing your translation off of the German localization (also in the SVN repository). Download them using right click -> save as, or using a SVN client such as TortoiseSVN to fetch the complete folder in one go.