My community, the Marians of the Immaculate Conception, has been promoting the message of the Divine Mercy for over 60 years! By 1950, we were printing holy cards and booklets about Divine Mercy in over 60 different languages and dialects. Currently, the Marians print the Diary of St. Faustina in Polish, English and Spanish. Additionally, the Diary has been published in Italian (by the Vatican), Portugese, French, German, Russian, Hungarian, Czech and Slovak.
Currently Arabic and Chinese versions are in the works. Fr. Seraphim was just in Hong Kong for a month, working on the Chinese version. If there are other language versions out there that I don't know about, please let me know! The Lord told St. Faustina to tell all the world about His great Mercy!