When Jews wrote in these languages they also used the Hebrew alphabet. For example, Jews living between Spain and Iraq spoke and wrote in Arabic. But when they wrote Arabic, they wrote it using the Hebrew letters. Same goes for Yiddish, Ladino and I saw a Torah translation in Farsi written in Hebrew letters.
An example in Yiddish: היינט איז זונטאג - haynt iz zuntog - today is sunday
An example in Arabic: אליום הו יום אלאחד - al-yawmu huwa yawmu 'lahad
Naturally, the level of care in writing varied from high accuracy when copying a Torah to quick casual writing when writing a personal letter. In casual writing the letters were rounder, some letters were connected.
Here is an example of carefully handwritten sentence from a Torah scroll:
Here is the first sentence of Mishnah from a handwritten manuscript:
The letters are also written carefully because it is an important book but here a scribe omits 'tags' over letters, adds marks in and around the letters, does not keep distance between the letters and does not always observe the proportion within and among the letters.
And here is a draft of Rambam's Mishneh Torah written by Rambam himself:
As you see, Rambam was quickly writing a draft for himself, not for publication and this is how standard letters naturally develop into cursive.
The most extreme forms of cursive developed in the Muslim countries by the eleventh century CE in parallel with the development of the Arab scripts.
Here is an example by Yehuda Halevi:
Because Jews lived over vast territory stretching from Morocco and West Europe all the way to Central Asia, the casual (cursive) script varied from place to place.
One famous example of a local cursive is Rashi script based on the cursive of the Sephardi Jews.The letters are also written carefully because it is an important book but here a scribe omits 'tags' over letters, adds marks in and around the letters, does not keep distance between the letters and does not always observe the proportion within and among the letters.
And here is a draft of Rambam's Mishneh Torah written by Rambam himself:
As you see, Rambam was quickly writing a draft for himself, not for publication and this is how standard letters naturally develop into cursive.
The most extreme forms of cursive developed in the Muslim countries by the eleventh century CE in parallel with the development of the Arab scripts.
Here is an example by Yehuda Halevi:
Because Jews lived over vast territory stretching from Morocco and West Europe all the way to Central Asia, the casual (cursive) script varied from place to place.
Since most Jews who were instrumental in founding the State of Israel came from the Yiddish speaking areas of Eastern Europe, their cursive became the official cursive in Israel and the most, if not the only, cursive used by Jews worldwide.
You can find numerous samples by looking up כתב עברי רהוט in Google's image search.
In Hebrew the cursive is called רהוט (rahut). רהוט means 'smooth' in Hebrew and 'running','cursive' in Aramaic.
There is an outstanding book about this subject by an Israeli linguist Edna Yardeni: The Book of Hebrew Script.
