Izchak Miller was a Professor of Philosophy who taught at MIT and Stanford, amongst other places, and was employed at Xerox PARC for a while. Izchak joined the DevTeam in 1986, at which time he was working at the University of Pennsylvania. He was, in fact, one of the founding members of the DevTeam, and was instrumental in synchronizing and arbitrating the team for a long time, up until the release of version 3.1.3. He personally wrote much of the shopkeeper code, as well as major contributions to prayer, alignments, and the version 3.1 rewrite of Gehennom.
Izchak died on the 1st of April 1994 from complications due to cancer, at the age of 58. The DevTeam dedicated NetHack 3.2 in his memory and added a shopkeeper named Izchak, in addition to the already-existing random possibility for tool shopkeepers of the name Kachzi Rellim (an anagram of his name). It is considered very poor form to mistreat this particular shopkeeper, despite the extent to which his co-workers are maligned by everyone.