Well... I dunno if you know phpMyAdmin. It's a mysql front-end made in PHP.
If I talk to you about this one it's because it has a nice multi-language system, with plain text files (not true plain text but almost the same
). To my mind this would be the easiest way to make the things.... Indeed it would allow you to add new languages or fix the files without the need to recompile the program each time. And would allow you to put "languages packs" to download.
Whatever, Im still oki to help you with french translation.
To have a look at phpMyAdmin :
http://www.sourceforge.net/projects/phpmyadmin