Wow, internationalization is always a fun one. I've worked on precisely one i8n
project, so my knowledge is pretty limited (and it was English-Welsh, which isn't a big
target audience; I'd hope the principles are similar. I'm originally from England, with
a Welsh mother - I've just been in the US for 20+ years and largely lost my accent).
That particular project only translated documentation and webpages;
configuration and source code stayed strictly in English.
IIRC, we ended up with a set of "template" pages in each supported language,
with markup indicating "program puts X here". All of the programmatically
generated text was fed into a string table, and the template system
substituted the appropriate locale's (selected by the user) template
and then filled in the appropriate strings from the string table. It worked, I do
remember that some of the translations were really tricky. Ordering changes
a lot. For example "Herbert is not a valid name" is "Nid yw Herbert yn enw dilys"
in Welsh (I think; haven't spoken it for decades, but I checked with Google
Translate and it looks right).
Non-latin character-set languages become painful, really fast. Validation is
really hard when there are multiple different ways of producing "Können"
(it's valid to use the
ö character, it's also valid to use an o with modifiers).
I had some fun with that one in Rust Brain Teasers:
Rust has pretty good support for most of the common i8n systems, and
UTF-8 is its default character set. It looks like Python is in pretty similar
shape. So there isn't a big barrier there, beyond deciding where i8n fits
into the project, how deep it needs to be, and finding translators!
As for the billing side.. I'm not sure that's LibreQoS's problem (yet). Ideally,
we'd become popular enough that vendors want to support our integrations,
and have a rich-enough API to make supporting Libre not hurt. I know I'd
rather not try and go head to head with all of the various billing vendors...
It looks like UISP has a pretty good language and currency list - but I've
NO idea how it works with payment processors overseas. I remember
PayPal giving me all manner of troubles when I did some (free) consulting
work for a fellow in Poland who decided to tip me what turned out to be a
small fraction of a US dollar. :-|