Weblate is a copylefted libre software web-based continuous localization system, used by over 2500 libre projects and companies in more than 165 countries.
In July 2019 (starting with the 3.7.1-6 tag), the containers is not running as root. As a consequence this has lead to changed exposed port from 80 to 8080.
Detailed documentation is available in Weblate documentation:
https://docs.weblate.org/en/latest/admin/install/docker.html