All the people who have ever contributed anything at translate.koha-community.org
One of the things that makes Koha so good, is the countless hours and hours of work that people all around the world put into translating it into their languages.
There are a lot (and when I say a lot, I mean a metric craptonne) of strings for people to translate. We also don’t make it easy for them by switching out templating engines, and constantly adding more strings, but they keep trucking along keeping the translations up to date.
So keep on keeping on, every string you translate, a kitten smiles.