In my browser console:
> Intl.NumberFormat.supportedLocalesOf('it')
["it"]
In node on my computer:
> Intl.NumberFormat.supportedLocalesOf('it')
[]
In node on my coworkers computer:
> Intl.NumberFormat.supportedLocalesOf('it')
["it"]
Same versions of node 4.5.0
Where is the Intl.NumberFormat support supposed to come from? What do you have to build to get it included in your version of node?