You can use Active Collab in Czech, Dutch, French, German, Italian, Polish, Portuguese, Serbian, Spanish, Swedish, and Turkish.
Changing language is easy. Once you’re in Active Collab, click on your name in the lower left corner and then Profile. There you set your personal preference for the language.
Want to change language for all new users, so when you invite someone, they can start using Active Collab right away in their native language? You can do that in System Settings > General Settings.