IBM

IBM's influence is etched into the very infrastructure of enterprise. Founded in 1911, it invented the hard disk drive in 1956, the ATM in 1967, the UPC barcode in 1973, and the relational database in 1970—a quartet that underpins virtually every transaction system today. For decades, it was the world's largest tech company, pioneering mainframes that defined corporate IT and, by 1990, holding more U.S. patents than any desktop rival.