The earliest know developers of nightmare frames were the Ashford Foundation and their development of the third generation Ganymede and the Io series however, both of those models were cancelled at the prototype stage because the Ashford Foundation closed down. The cost to develop the nightmares were too high and Milly's grandfather was too much of a fan of old fashioned extravagant parties. After that he used his party connections to move to Area 11 and to become principal of what is now known as the Ashford Academy.

They talk about all this in the second picture drama, stage 3.25.

Aside from Milly's grandfather the only other known developers are Lloyd, Cecile, and Rakshata.