Desktop developers are the engine of a plethora of software activity. They are the subject of this report. We estimate their numbers, their distribution across geographies and platforms, as well as the goals of desktop developers and their means to make money. We also derive estimates of the addressable market for technologies that are used by desktop developers. Our estimate draws on data from over 40,000 desktop developers in 140+ countries surveyed in 2015 and 2016.