Aharon Varady, founding director of the Open Siddur Project, is a copyright researcher and amateur book scanner. He prepares digital images and new digital editions of prayer books and related works in the Public Domain in order to make their constituent parts (prayers, translations, annotations, etc.) publicly accessible for collaborative transcription by project volunteers. (In some cases, he finds existing digital editions prepared by others that require correction and reformatting.) If you appreciate his efforts, please send him a kind note or contribute to his patreon account.

Gavro Schwarz (also Gabor Schwarz and sometimes Gabriel Schwarz; 1872–1942), born in Nadědvár (Kingdom of Hungary), was a Croatian rabbi, military chaplain, chief rabbi of the Jews of Zagreb, and historian of Croatian Jewry. Between 1886 and 1891, he studied at the Rabbinical Seminary in Budapest and later at the Rabbinical Seminary in Vienna, graduating in 1897. While there, he also studied at the University of Vienna where he majored in German and Hungarian literature, and in 1896 completed a doctorate in theology. In 1893, he was appointed chief rabbi of the Jews of Karlovy Vary. In 1901 he moved to serve in the rabbinate in Zagreb. During World War Ⅰ, between 1914 and 1915, he served as a rabbi in the Austro-Hungarian army. From 1901 until his retirement in 1926, he held various teaching positions in general secondary schools in Zagreb, in Talmud Torah, and at the University of Zagreb. In 1906 , he was appointed assistant to the chief rabbi Hoshea Jacobi (1841-1925). Between 1923 and 1926 he served as the chief rabbi of the Jews of Zagreb. He was engaged in general public activity in the city and founded the Croatian-Jewish Literary Association. He wrote several history books, and in addition published dozens of articles and studies about Croatian Jewry. At the beginning of his career, Gabro Schwartz was among the opponents of the Zionist movement, and only towards the mid- 1930s did he gradually change his position and begin to support the Zionist idea. He guided and taught youth at the "Beit Israel" youth association in Križevci until 1940. During World War Ⅱ, after the occupation of the Kingdom of Yugoslavia by Nazi Germany and the establishment of the puppet government of the Ustasha, persecution of Jews began. Gavro Schwarz was arrested together with his family. After a few months he was released. In February 1942 he died of illness and was buried in the Mirogoj cemetery. The chronicles and studies he published describe the beginning of Jewish settlement in Croatia until the modern era , focusing on the Jews of Zagreb in the 19th century.