Most of the major European languages have an IF community. I think the Spanish community is the strongest. They are very active. Adventuron and DAAD are popular.
Most of the major European languages have a replacement for the standard Inform 6 library. These take care of any syntactic issues in the English parser, as well as replacement of the standard verbs.
There are a lot of language-specific authoring systems, but most of these are no longer used. Here’s a quick run-down of the ones I’m aware of:
Adrift 3.9 has games in French, Russian and Spanish. Adrift 4.0 has games in French, Italian and Spanish. Adrift 5.0 has a game in Danish.
AGE has a game in Spanish.
AGT has a game in Dutch.
Alan 2.6 & 2.8 have games in German. Alan 3.0 has a game in Spanish.
AWS has games in Italian.
CAT (not the English one) has games in Spanish.
Floyd has games in German.
JACL has a game in French.
MAC (Mystery Adventure Creator) has games in Italian.
ngPAWS has games in Spanish.
Quest 5 has at least one game in Spanish.
SINTAC has games in Spanish.
TADS 2 has games in Russian.
TADS 3 has games in Czech, German, Italian & Spanish.
TAG (not the English one) has games in German.
TxA has games in German.
Visual SINTAC has games in Spanish.
YaBasic has a game in Italian.
And, of course, good old Inform 6 has games in Dutch, French, German, Italian, Lobjan, Spanish & Swedish.