The Biology of Software

Alan Kay did not invent object-oriented programming by sitting at a terminal and writing a new kind of code. He imported a biological metaphor into a field that had been thinking in mechanical metaphors since its inception, and the metaphor changed what the field could imagine. The mechanical paradigm treated a program as a sequence of instructions executed in order, data flowing through like material on an assembly line. Kay had studied biology, and he understood how cells work: each cell is a self-contained unit that carries its own instructions, maintains its own state, and communicates with other cells through chemical messages without requiring any cell to understand the internal workings of any other. From this communication, from millions of self-contained units exchanging messages according to their own internal logic, an organism emerges that is vastly more capable than any individual cell. Software, Kay