Probably none of the kids today know him anymore - the inventor of APL and J. Two of the strangest and most interesting programming languages. His work certainly influenced many programmers and language designers, and in my opinion, he deserves to be seen on the same level as McCarthy (Lisp inventor), Kristen Nygaard (Simula and thus OO inventor) and Alan Kay (Smalltalk father). After Kristen Nygaard, he was the second great figure in language design to pass away.