Haiku's Locale Kit: Catalogs, Formatting, and Runtime Language Selection
How native Haiku applications separate translatable strings from code and format dates, numbers, and time for the active locale.
The Locale Kit gives native applications message catalogs and locale-aware formatting rather than encouraging hardcoded translated strings. Source text is marked for lookup, catalogs provide language-specific values, and the system selects the appropriate catalog at runtime.
Translation is more than replacing words. Plurals, date order, decimal separators, collation, text direction, and control sizing can change. Interfaces must leave room for longer labels and avoid constructing sentences from fragments translators cannot reorder.
Keep stable context for ambiguous strings, update catalogs when source messages change, and test with more than one Latin-language locale. A missing translation should fall back predictably instead of producing an empty control.
Sources: Haiku Locale Kit API, Haiku localization guide