I\'m currently using .resx files to manage my server side resources for .NET.
the application that I am dealing with also allows developers to plugin Ja
JSGettext does an excellent job -- dynamic loading of GNU Gettext .po files using pretty much any language on the backend. Google for "Dynamic Javascript localization with Gettext and PHP" to find a walkthrough for JSGettext with PHP (I'd post the link, but this silly site won't let me, sigh...)
Edit: this should be the link