So VisiCalc came and went, but the software genre it pioneered – the spreadsheet – endured to become arguably the most influential type of code ever written, at least in the sense of touching the lives of millions of office workers. I’ve never worked in an organisation in which spreadsheet software was not at the heart of most accounting, budgeting and planning activities. I’ve even known professionals for whom it’s the only piece of PC software they’ve ever used: one elderly accountant of my acquaintance, for example, used Excel even for his correspondence; he simply widened column A to 80 characters, typed his text in descending cells and hit the “print” key.