Leads me to believe that the decimal separator "." is hard-coded, rahter than taken from the locale.
Note that for example in Germany "," is the proper decimal separator.
Not sure what you're talking about. Do you mean this line? I think it splits the number according its toString representation, which is locale independant.
The code in
https://github.com/andyearnshaw/Intl.js/blob/master/src/11.numberformat.js
Leads me to believe that the decimal separator "." is hard-coded, rahter than taken from the locale. Note that for example in Germany "," is the proper decimal separator.