The list of people who've put work into Zammad, in alphabetical order:

André Bauer (https://github.com/monotek)
Martin Edenhofer (https://github.com/martini)
Roy Kaldung (https://github.com/rkaldung)
Johannes Nickel (https://github.com/hanneshal)
Felix Niklas (https://github.com/mrflix)
Daniel Obée (https://github.com/tisar)