If you would like to translate GIB into a new language, we would love to have you do it! In exchange, you'll get a copy of GIB, and the right to buy additional copies at half off.
The translation involves translating a bunch of strings, modifying GIB's card images as appropriate for your country, and modifying the convention card as well. The materials which need to be translated are all in the translat.zip file in this directory. In the case of the convention card, while a literal translation is acceptable, it would be better to instead create a new image of identical dimensions that is closer in appearance to your local convention card (if the equivalent notion exists). After the convention card image is modified, you'll need to update the layout file appropriately (the format is described at the top of the layout file itself).
If you do decide to translate GIB into a new language, please let us know so that we can coordinate the effort, avoiding having multiple people translate GIB into the same language.