Advanced Installer comes with a multitude of languages built-in, but there are cases when you need to localize a new language or change an existing one.
Localizing a new language can be done by going to the Translations page, checking your desired language from the list and adding the texts in the Projects strings tab. Here you can also change the texts for all other languages.
Translating and using a new language
More about Multilingual Packages
To learn more about languages see our documentation.