The Delft University of Technology (TUD) deployed her first generation of massive open online courses (MOOCs) in 2013-2014 delivered through the edX platform. These DelftX MOOCs were engineering courses designed at the level equivalent to that of a bachelor-program entry level. Almost 140 thousand students registered, around 3,7% received certificates of completion, and the rest participated to a degree reflective of their needs. To better understand and ultimately enhance the MOOCs, TUD conducted the collection and analysis of data about learners and their contexts. This exploratory paper focuses on the specific analyses pertinent to describing the demographics of an Engineering MOOC participant, as observed in the first generation of TUD MOOCs. The implications of the observed participant demographics are analysed and discussed.