VisiCalc (1979)

VisiCalc 🥇First Commercially-Released Computer Spreadsheet Program  VisiCalc, released in October 1979, was the "killer app" that single-handedly transformed the personal computer from a hobbyist's toy into an essential business tool. Conceived by Dan Bricklin while watching a Harvard Business School professor laboriously erase and recalculate a financial table on a blackboard, and programmed by Bob Frankston, VisiCalc introduced the world to the electronic spreadsheet. By allowing users to change a single value and watch every related cell update instantly, it provided a "magic sheet of paper" for "what-if" financial modeling that previously required $20,000 minicomputer software. Its initial exclusivity to the Apple II was so powerful that many business owners famously bought the $2,000 hardware just to run the $100 software, fueling Apple's early dominance. Though it was eventually superseded by Lotus 1-2-3 and Microsoft Excel, VisiCalc’s legacy as of 2026 remains foundational; it d