Dunash Ben Librat (mid 10th century) was perhaps of Baghdadi origin, but he was educated in Fez. He studied with Saadiah Gaon in the Sura Academy and also lived for a time in Cordoba. Dunash is best remembered for a controversy that he instituted with Menahem Ibn Sharuk. Menahem was the author of a Hebrew Grammar that Dunash disputed. His attacks were particularly vicious and cogent, and as a result, Menahem fell out of favor with his patron, Hasdai Ibn Shaprut. Rashi, the great French commentator, was aware of the argument between the two and quotes Dunash about 20 times. Within the field of poetry, Dunash is widely credited with applying Arab style to Hebrew poetry. Solomon Ibn Gabirol extols Dunash as the greatest Hebrew poet of all time. He is the author of the Sabbath song, Dror Yikra.
Sources: This material was originally published in Sparks! - an e-zine for Jewish families located on the Internet at http://www.sparksmag.com