Zarphatic or Judæo-French (Zarphatic: Tsarfatit) is an extinct Jewish language, formerly spoken among the Jewish communities of northern France and in parts of what is now west-central Germany, in such cities as Mainz, Frankfurt am Main, and Aachen.
The word Zarphatic comes from the Hebrew name for France, Tzarfat (צרפת), the Biblical name for the Phoenician city of Sarepta. Some have conjectured that Zarphatic was the original language of the Jews who eventually adopted Old High German, which led to the development of Yiddish.
Zarphatic was written using a variant of the Hebrew alphabet, and first appeared in the 11th century, in glosses to texts of the Hebrew Bible and Talmud written by the great rabbis Rashi and Rabbi Moshe HaDarshan. Constant expulsions and persecutions, resulting in great waves of Jewish migration, brought about the extinction of this short-lived, but important, language by the end of the 14th century.
One feature of Zarphatic spelling, that sets it apart from most other Indo-European Jewish languages, is that to represent vowel sounds, rather than using Hebrew letters with no matching phonemes in the language, it instead made extensive use of the Tiberian system of niqqudot to indicate the full range of Old French vowels.
Another interesting feature of Zarphatic is that it displays relatively few Hebrew loanwords. This sets it apart from the vast majority of other Jewish languages, and may indicate that it is not actually a distinct language, rather a dialect of Old French, or simply Old French, written using a different orthography. (Old French did not have a written standard.)