The Past, Present, and Future of Software Evolution By jcamposl Period: 500 BCE to 1945 Zero Generation Machnes and gears Period: 1946 to 1959 First Generation Vacuum tube Period: 1959 to 1965 Second Generation Transistor Period: 1959 to 1965 Third Generation Integrated Circuits Period: 1971 to 1989 Fourth Generation VLSI Period: 1989 to 2021 Fifth Generation IA