iWork'09 retail installation DVD : does the language and/or region matter?

**Does iWork'09 retail DVD allow installation in any language or shall one care about it?** - Example: Can on install iWork in German from a DVD purchased in the US? **Is iWork'09 retail DVD the same worldwide, or is it region-specific or country-specific?** - Example: Can a European user install iWork from a DVD that was initially commercialized on another continent. - Example: Can a user in Belgium use a DVD that was initially commercialized in France?