It is not known for certain who authored the Haggadah.
Eugen Verber has written: 'The Sarajevo Haggadah' -- subject(s): Haggadah, Illustrations, Jewish Illumination of books and manuscripts, Sarajevo Haggadah
Mordekhai Elon has written: 'The Tekhelet Mordekhai Haggadah' -- subject(s): Haggadah, Judaism, Liturgy, Seder
Yes.
Chaim Miller has written: 'Haggadah =' -- subject(s): Liturgy, Judaism, Texts, Seder, Teachings, Haggadot, Haggadah
Yaakov Wehl has written: 'The Haggadah with Answers'
A Haggadah is a book that contains the religious ceremony for the first night of Passover (outside of Israel the ceremony is held on the first 2 nights of Passover).
Elaine Moise has written: 'The dancing with Miriam Haggadah' -- subject(s): Adaptations, English, Haggadah, Jewish women, Passover, Prayer-books and devotions, Seder
Labor Zionist Alliance has written: 'Passover Haggadah'
Hillel Bakis has written: 'Haggadah de Tou BiChevat'
Jacob Freedman has written: 'Polychrome Historical Haggadah For Passover'
The Haggadah contains the service for the seder.
Gershon Weiss has written: 'Samson's struggle' -- subject(s): Bible, Biography, Commentaries 'The Holocaust Haggadah'