I'm thinking about one language file per language with all the variables are translated into the specific language.
I'll try to make it some more clear by showing some code, the structure is: [variable] = 'translated text':
English language file
$lang_main_menu['home_title'] = 'Go to the home page';
$lang_main_menu['home_lnk'] = 'Home';
$lang_main_menu['alb_list_title'] = 'Go to the album list';
$lang_main_menu['alb_list_lnk'] = 'Album list';
$lang_main_menu['my_gal_title'] = 'Go to my personal gallery';
$lang_main_menu['my_gal_lnk'] = 'My gallery';
$lang_main_menu['my_prof_title'] = 'Go to my personal profile';
$lang_main_menu['my_prof_lnk'] = 'My profile';
Dutch language file
$lang_main_menu['home_title'] = 'Ga naar de beginpagina';
$lang_main_menu['home_lnk'] = 'Beginpagina';
$lang_main_menu['alb_list_title'] = 'Ga naar de albumlijst';
$lang_main_menu['alb_list_lnk'] = 'Albumlijst';
$lang_main_menu['my_gal_title'] = 'Ga naar mijn persoonlijke galerij';
$lang_main_menu['my_gal_lnk'] = 'Mijn galerij';
$lang_main_menu['my_prof_title'] = 'Ga naar mijn persoonlijk profiel';
$lang_main_menu['my_prof_lnk'] = 'Mijn profiel';
As I am Dutchspeaking (from Flanders in Belgium) I think there are people interested for a Dutch version of the great HTML editor.
I'm almost certain there will be volunteers to (help) translate these texts.
(I'm one of them! )