In the preferences menu, the language can be selected as English, French, German, or Spanish. This will control how the URL is written and how the Google map window displays, but it will not change the labeling of the Locator buttons, text fields, or menus. Your preferences will be implemented on the next URL that you build and they will be saved when you quit Locator.
Locator will also save all of your settings from your last search when you quit, and will reload them when you launch the program the next time.