Agelong Tree has multilingual interface. Different languages for program's interface are supported and the language of the interface can be changed in the "Tree" - "Language" menu, even without program's restart.

The following interface languages are included into the installation^*:

Arabic
Armenian
Bulgarian
Byelorussian
Chinese Simplified
Croatian
Czech
Dutch
English
Estonian
French
Galician
German
Hungarian
Italian
Latvian
Lithuanian
Polish
Romanian
Russian
Serbian
Slovak
Spanish
Turkish
Ukrainian

^*Listed alphabetically