Babel is the multilingual environment for LaTeX (tailored for
LuaTeX, pdfTeX and XeTeX), and sometimes Plain. Its aim is to
provide a comprehensive localization framework for different
languages, scripts and cultures based on the latest advances on
international standards (Unicode, W3C, OpenType). It supports
about 300 languages (with various levels of coverage) across
about 45 scripts, including complex (like CJK, Indic) and RTL
ones. Besides the traditional .ldf files, there are many
locales built on a modern core that utilizes descriptive .ini
files, with tools providing precise control over hyphenation
and line breaking, captions, date formats (across various
calendars), spacing, transliteration, numbering and other
locale-specific typographical rules.

Homepage:
https://ctan.org/pkg/babel
