In 1912 Flugzeugwerke Gustav Otto (Otto) of Munich founded a branch company Ago (Ago Flugzeugwerke GmbH) in Berlin-Johannisthal, originally known as Aerowerke Gustav Otto. Early in the war Ago produced several distinctive twin-boom designs, but they also delivered tractors such as the C.IV. In 1917 Ago went into liquidation.
Ago also built a handful of floatplanes for the German Navy in ones and twos, including some designed from the C.I and C.II.
Production aircraft from the Great War or shortly thereafter include:
- Gray, p.13.
- Lamberton, p.160.
- Nowarra, p.80.
- Peter Gray and Owen Thetford. German Aircraft of the First World War. Great Britain, Putnam, 1962, 1987. ISBN 0-85177-809-7.
- W.M. Lamberton and E.F. Cheesman, Reconnaissance & Bomber Aircraft of the 1914-1918 War. Great Britain: Harleyford Publications Ltd., 1962.
- Heinz J. Nowarra, Bruce Robertson, and Peter G. Cooksley. Marine Aircraft of the 1914-1918 War. Letchworth, Herts, England: Harleyford Publications Limited, 1966. ISBN 0900435070