Comshare, Inc, of Ann Arbor, Michigan, was the second most important corporate customer; Tymshare, Comshare and UC Berkeley collaborated in much of the operating system development for the SDS 940. Douglas Engelbart's Augmentation Research Center (ARC) used an SDS 940 for their oN-Line System, more commonly known as NLS. It was with this computer that he gave The Mother of All Demos in December 1968, heralding many of the concepts associated with personal computing today. The first host connected to the ARPANET was an SDS 940 at SRI in October, 1969.