The List & Label Designer can be displayed in several languages (depending on the edition). Besides the Designer, the printer, preview and export dialogs are localized as long as they are not made up of common dialogs which are localized by the OS.
In order to integrate a language, use the corresponding language constant for LlJobOpen() or set the "Language" property to the desired value when using a component. Also supply your customers with the language files (cmll29??.lng, cmls29??.lng). List & Label expects the files to be in the same path as the main DLL cmll29.dll.