Ryzom

You clone existing language files from the client and server and change the language setting in the client.
Or you can use the translation tools.

Where can I find these files?

Server side:
code\ryzom\server\data_shard\language

Client side:
data\gamedev.bnp
You can unpack it with bnp_make or bnp_manager (ovqt plugin).

The translation tools are in:
code\ryzom\tools\translation_tools