Brian Harvey on Software Complexity

  • > "Computer programming is so easy as long as the program that you're writing is small so it can all fit in your head at once, which is how it used to be in the old days..."

    Actually, a lot of what we learned about writing big programs, we learned in the "old days". For example, The Mythical Man Month is about the design of the operating system for the IBM 360 in the 1960s. There were also plenty of big and complicated compilers (PL/I, Algol 68) written in the old days.

    ARPANET, the precursor of the internet, was created in the 1960s. So was the software that ran the Apollo space missions. Remember the iconic photo of Margaret Hamilton standing next to the stack of printouts for the Apollo software that was as tall as she was?[1] Certainly too big for one programmer to keep in her head.

    So the assumption that in the old days, all programs were small and fit entirely into peoples' heads isn't really true. Writing significant software systems back then was as much about control of complexity as it is today.

    [1] https://en.wikipedia.org/wiki/Margaret_Hamilton_(software_en...