Visicalc, the first spreadsheet computer program for personal computers, made its debut at the West Coast Computer
Faire in San Francisco on May 12, 1979. The innovative spreadsheet grid, still in use today and years ahead of its time was invented by Dan Bricklin. It was described as "a magic sheet of paper that can perform calculations and recalculations". VisiCalc was the original killer app. Many people bought $2,000 computers to run the $100 software. Happy Birthday!