Starting with OpenMediaVault 0.3 the WebGUI supports internationalization (i18n). Because of that translators are wanted helping to support as much languages as possible. To become a translator you have to do the following:

Subscribe the OMV contributor license agreement. You can download it here.

Create an account at Transifex, the service used for collaborative translation. You can create it here.

After your account has been enabled you can start translating.