Different languages are completed to different degrees. They are released as is. If you use an incomplete translation, you'll see bits of English in the game.
You personally can help completing them. Discussion is here.
Current languages:
- Czech, based on files from Drobovik's database.
- French, based on translation for RP 2.3.3.
- German, based on translation for RP 2.1.2b (file).
- Italian, based on translation by Ragfox with updates by Zhanka.
- Polish, based on translation for RP 2.3.3.
- Portuguese includes parts from translation by rsalvarenga found in Drobovik's database.
- Russian, based on 1C + Drobovik & Co.
- Spanish, based on translation v1.0 by ClanDLAN for Fallout 1.02d.
If you want another language added into the system so that you can start translating into it, post on the forum.