Aubrey Chernik's MVS Performance Monitor. Barry Merrill would have been the first user of Omegamon, but when Aubrey showed up in Dallas while Barry was still at Sun Oil, with a version that required a dedicated terminal (instead of being run from a TSO terminal, so the monitor's address space could be cancelled if there was a problem as was common with early MVS monitors), Barry did not have the clout to get it installed, and thus the first customer was someone else.