This firm, first known as Mollo u. Witzendorf, published mainly light music in Vienna from 1842 to 1871. Eduard (1799–1842) and Florian (1803–1869) Mollo were sons of Tranquillo Mollo (1767-1838) who founded Mollo in 1798.
Witzendorf published many songs and piano pieces by composers such as J.H. Doppler, and a long series of 25 opera potpourris called Opern-Halle: neueste Sammlung von Potpourris aus den beliebtesten Opern ; arrangirt für das Pianoforte allein (1846-56). Items for strings were provided by Stransky for cello and Dont and Hauser for the violin, including both Dont's famous studies such as the 3 Caprices, Op.20 and a 10-volume series of arrangements known as Musikalische Unterhaltung (1846-48).