The following 3rd party packages are involved in the EdX Platform translation efforts:

Django

• https://docs.djangoproject.com/en/1.11/topics/i18n/

• Does message extraction to .po files and uses generated .mo files to actually do translations

Transifex

• https://docs.transifex.com/integrations/django/

• Service that actually handles translations, has specific Django support

• Accepts .po files in English

• Returns localized .po files

• Has mapping in the config that should allow us to get the correct filename

Babel

• https://github.com/python-babel/babel

• Python package that enhances message gathering, especially for non-.py file types

django-babel

• https://github.com/python-babel/django-babel

• Python package for helping Babel extract messages from Django-centric file types (.html, .txt, .js)

django-babel-underscore

• https://github.com/EnTeQuAk/django-babel-underscore

• Python package for helping Babel extract messages from underscore.js templates

django-static-i18n

• https://github.com/zyegfryed/django-statici18n

• Python package that generates pre-translated javascript files

mako

• http://docs.makotemplates.org/en/latest/usage.html?highlight=babel#babel

• Python templating engine, provides its own Babel extraction interface

gettext and friends

• GNU fundamental project, actually handles performing string translation using compiled .mo files (and much more) 

pavelib

• https://github.com/edx/edx-platform/blob/master/pavelib/i18n.py

• Platform wrapper around edx's i18n-tools

i18n-tools

• https://github.com/edx/i18n-tools

• Wrappers that handle the details of Transifex integration, message extraction, and compiling messages