We are currently refactoring our application in order to use multiple languages. The application startet 1997 and later it supported 2 fix languages. So it's one defined language or the other, this was used in uncountable places. Now a team of 6 developers has to refactor all the code of the last 20 years, where labels are used and an old translator was magically used out of nowhere..
Turns out it's a ton of work to get the software ready for really multiple language support.