| IdentityTranslator | IdentityTranslator does not translate anything. |
| Interval | Tests if a given number belongs to a given math interval. |
| MessageCatalogue | MessageCatalogue. |
| MessageSelector | MessageSelector. |
| PluralizationRules | Returns the plural rules for a given locale. |
| Translator | Translator. |
Interfaces
| MessageCatalogueInterface | MessageCatalogueInterface. |
| TranslatorInterface | TranslatorInterface. |