Loading locales in the browser just requires you to include the locale files. Be sure to specify the charset to prevent encoding issues.
<script src="locale/fr.js" charset="UTF-8"></script>
moment.locale('fr'); // Set the default/global locale
To minimize HTTP requests, use our Grunt task to compile with a custom list of locales:
grunt transpile:fr,it
Note: Locale files are defined in UMD style, so they should work seamlessly in all environments.