Weblate is libre software web-based continuous localization system, used by over 2500 libre projects and companies in more than 165 countries.
Hosted Weblate customizations
These customizations are used on the Hosted Weblate service.
You can use them as an example how to customize Weblate, but there are probably not generally usable. If you think something should be part of Weblate, please open an issue.