In GeoMedia what is the C:\ProgramData\Intergraph\QD folder used for?
The C:\ProgramData\Intergraph\QD folder stores the Object Space Data Server files. Prior to GeoMedia 2015 the Object Space Data Server was a separate install, but was included for the first time in GeoMedia 2015.
The Object Space Data Server has to read the schema definition from the Dynamo data dictionary before it can display the contents of a Dynamo object space. The QD files from Dynamo allow the ability to read the data dictionary.