Hi Aaron,

We don’t have any plans of open sourcing this right now. But honestly, it’s radically simple, just a single switch statement implemented in each language we use. We asked our writers and translators for guidelines on how to handle posessives in each language. There are some stylistic choices to be made in some languages. I can summarize the rules here.

Given a string name:

• English:{name}’salways (turns out the old rule about not adding ’s if the name ends in s is not considered necessary)
• Spanish: de {name} always
• French: de {name} or d’{name}, the latter for names beginning with a vowel
• German: {name}s or {name}’, the latter for names ending in [sßxz]
• Japanese: {name}の

We have a second version that just gives the suffix/prefix for when we want to linkify the user’s name but not the possessive.

The other guideline here is that when used in a sentence, we always name the ICU variable {user_possessive} so that our translators know it will be a posessive noun like Scott's .